Prodrugs of Nrf2 activating compounds and uses thereof

ABSTRACT

Aspects of the present disclosure include prodrugs of compounds that activate Nrf2. Such prodrugs find use in the treatment of autoimmune and inflammatory diseases and disorders, such as for example psoriasis and multiple sclerosis. Embodiments of the present disclosure also relate to pharmaceutical compositions that include these prodrugs, methods of using these prodrugs in the treatment of various diseases and disorders, processes for preparing these prodrugs and intermediates useful in these processes.

This application is a continuation application of U.S. application Ser. No. 16/412,217, filed May 14, 2019, which claims the benefit of U.S. Provisional Application No. 62/672,458, filed May 16, 2018, the disclosures of which are incorporated herein by reference.

INTRODUCTION

Nuclear factor (erythroid-derived 2)-like 2, also known as NFE2L2 or Nrf2, is a transcription factor that in humans is encoded by the NFE2L2 gene. Nrf2 is a basic leucine zipper (bZIP) protein that regulates the expression of antioxidant proteins that protect against oxidative damage triggered by injury and inflammation.

Fumaric acid is an intermediate product of the citric acid cycle. Fumaric acid is a source of intracellular energy in the form of adenosine triphosphate (ATP), and is generated by oxidation of adenylsuccinate by the enzyme succinate dehydrogenase which is then converted to maleate by the enzyme fumarase. Fumaric acid esters (FAE), such as dimethylfumarate (DMF) have been used in the treatment of psoriasis and multiple sclerosis. After oral intake, DMF is rapidly hydrolyzed by esterases to its metabolite monomethyl fumarate (MMF).

Glutathione (GSH) is an antioxidant that can be synthesized in the body from the amino acids L-cysteine, L-glutamic acid, and glycine. Glutathione can be in a reduced state (GSH) or an oxidized state (glutathione disulfide, GSSG). The reduced form of glutathione (GSH) can act as an antioxidant by scavenging reactive oxygen species.

Multiple sclerosis (MS), also known as disseminated sclerosis or encephalomyelitis disseminata, is an inflammatory disease in which the insulating covers of nerve cells in the brain and spinal cord are damaged. This damage disrupts the ability of parts of the nervous system to communicate. The three main characteristics of MS are the formation of lesions in the central nervous system (also called plaques), inflammation, and the destruction of myelin sheaths of neurons. MS may be caused by either destruction of the myelin sheaths of neurons by the immune system or failure of the myelin-producing cells.

Psoriasis is a chronic relapsing/remitting immune-mediated skin disease characterized by red, scaly patches, papules, and plaques. There are five main types of psoriasis: plaque, guttate, inverse, pustular, and erythrodermic. Plaque psoriasis is the most common form and typical symptoms are red and white scaly patches on the top layer of the skin. Psoriasis is thought to be caused when the immune system mistakes normal skin cells for a pathogen, and secretes inflammatory chemical signals (cytokines) that cause overproduction of new skin cells.

SUMMARY

Aspects of the present disclosure include prodrugs of compounds that activate Nrf2. Such prodrugs may find use in the treatment of autoimmune and inflammatory diseases and disorders, such as for example psoriasis and multiple sclerosis. Embodiments of the present disclosure also relate to pharmaceutical compositions that include these prodrugs, methods of using these prodrugs in the treatment of various diseases and disorders, processes for preparing these prodrugs and intermediates useful in these processes.

Embodiments of the prodrugs are provided throughout the present disclosure. In certain embodiments, the prodrug is a compound represented by the following formula (I):

wherein:

R² is selected from the group consisting of sulfonyl, carboxyl, carboxyl ester, and aminoacyl;

R³ is selected from the group consisting of an active agent, an antioxidant, an amino acid, an amino acid derivative, a peptide, and a peptide derivative;

R⁴ is selected from the group consisting of hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, heteroaryl, and substituted heteroaryl;

X¹ and X² are each independently selected from N and CH, wherein at least one of X¹ and X² is N; and

n is an integer from 1 to 6,

or a salt or a stereoisomer thereof.

In certain embodiments, R² is sulfonyl or carboxyl ester.

In certain embodiments, the compound is a compound of formula (II):

wherein:

R³ is selected from the group consisting of an active agent, an antioxidant, an amino acid, an amino acid derivative, a peptide, and a peptide derivative;

R⁴ is selected from the group consisting of hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, heteroaryl, and substituted heteroaryl;

R⁵ is selected from the group consisting of alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, heteroaryl, and substituted heteroaryl;

X¹ and X² are each independently selected from N and CH, wherein at least one of X¹ and X² is N; and

n is an integer from 1 to 6,

or a salt or a stereoisomer thereof.

In certain embodiments, R⁵ is aryl or substituted aryl.

In certain embodiments, n is 1. In certain embodiments, n is 2.

In certain embodiments, R³ is glutathione. In certain embodiments, R³ is an amino acid or an amino acid derivative.

In certain embodiments, X¹ is N and X² is N. In certain embodiments, X¹ is N and X² is CH.

In certain embodiments, the compound is:

In certain embodiments, the compound is an isolated compound having the structure:

Aspects of the present disclosure include a pharmaceutical composition that includes a compound as described herein, and a pharmaceutically acceptable carrier.

Aspects of the present disclosure include a method of treating a disease or disorder in a subject in need thereof. The method includes administering to the subject a pharmaceutically effective amount of a compound as described herein or a pharmaceutical composition as described herein sufficient to treat the disease or disorder in the subject, where the disease or disorder is an autoimmune disease or an inflammatory disease.

In certain embodiments, the disease or disorder is psoriasis or multiple sclerosis.

DETAILED DESCRIPTION

Aspects of the present disclosure include prodrugs of compounds that activate Nrf2. Such prodrugs may find use in the treatment of autoimmune and inflammatory diseases and disorders, such as for example psoriasis and multiple sclerosis. Embodiments of the present disclosure also relate to pharmaceutical compositions that include these prodrugs, methods of using these prodrugs in the treatment of various diseases and disorders, processes for preparing these prodrugs and intermediates useful in these processes.

The prodrugs and compounds described herein may contain one or more chiral centers and therefore, the embodiments are directed to racemic mixtures; pure stereoisomers (i.e., enantiomers or diastereomers); stereoisomer-enriched mixtures and the like unless otherwise indicated. When a particular stereoisomer is shown or named herein, it will be understood by those skilled in the art that minor amounts of other stereoisomers may be present in the compositions unless otherwise indicated, provided that the desired utility of the composition as a whole is not eliminated by the presence of such other isomers.

Before the present invention is further described, it is to be understood that this invention is not limited to particular embodiments described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims.

It must be noted that as used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements, or use of a “negative” limitation.

Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is specifically contemplated. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges, and are also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the invention.

The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates which may need to be independently confirmed.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, the preferred methods and materials are now described. All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and/or materials in connection with which the publications are cited.

Except as otherwise noted, the methods and techniques of the present embodiments are generally performed according to conventional methods well known in the art and as described in various general and more specific references that are cited and discussed throughout the present specification. See, e.g., Loudon, Organic Chemistry, Fourth Edition, New York: Oxford University Press, 2002, pp. 360-361, 1084-1085; Smith and March, March's Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, Fifth Edition, Wiley-Interscience, 2001; or Vogel, A Textbook of Practical Organic Chemistry, Including Qualitative Organic Analysis, Fourth Edition, New York: Longman, 1978.

The nomenclature used herein to name the subject compounds is illustrated in the Examples herein. This nomenclature has generally been derived using the commercially-available AutoNom software (MDL, San Leandro, Calif.).

Terms

The following terms have the following meanings unless otherwise indicated. Any undefined terms have their art recognized meanings.

“Alkyl” refers to monovalent saturated aliphatic hydrocarbyl groups having from 1 to 10 carbon atoms and preferably 1 to 6 carbon atoms. This term includes, by way of example, linear and branched hydrocarbyl groups such as methyl (CH₃—), ethyl (CH₃CH₂—), n-propyl (CH₃CH₂CH₂—), isopropyl ((CH₃)₂CH—), n-butyl (CH₃CH₂CH₂CH₂—), isobutyl ((CH₃)₂CHCH₂—), sec-butyl ((CH₃)(CH₃CH₂)CH—), t-butyl ((CH₃)₃C—), n-pentyl (CH₃CH₂CH₂CH₂CH₂—), and neopentyl ((CH₃)₃CCH₂—).

The term “substituted alkyl” refers to an alkyl group as defined herein wherein one or more carbon atoms in the alkyl chain (except the C₁ carbon atom) have been optionally replaced with a heteroatom such as —O—, —N—, —S—, —S(O)_(n)— (where n is 0 to 2), —NR— (where R is hydrogen or alkyl) and having from 1 to 5 substituents selected from the group consisting of alkoxy, substituted alkoxy, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, acyl, acylamino, acyloxy, amino, aminoacyl, aminoacyloxy, oxyaminoacyl, azido, cyano, halogen, hydroxyl, oxo, thioketo, carboxyl, carboxylalkyl, thioaryloxy, thioheteroaryloxy, thioheterocyclooxy, thiol, thioalkoxy, substituted thioalkoxy, aryl, aryloxy, heteroaryl, heteroaryloxy, heterocyclyl, heterocyclooxy, hydroxyamino, alkoxyamino, nitro, —SO-alkyl, —SO-aryl, —SO-heteroaryl, —SO₂-alkyl, —SO₂-aryl, —SO₂-heteroaryl, and —NR^(a)R^(b), wherein R′ and R″ may be the same or different and are chosen from hydrogen, optionally substituted alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, aryl, heteroaryl and heterocyclic.

“Alkylene” refers to divalent aliphatic hydrocarbyl groups preferably having from 1 to 6 and more preferably 1 to 3 carbon atoms that are either straight-chained or branched, and which are optionally interrupted with one or more groups selected from —O—, —NR¹⁰—, —NR¹⁰C(O)—, —C(O)NR¹⁰— and the like. This term includes, by way of example, methylene (—CH₂—), ethylene (—CH₂CH₂—), n-propylene (—CH₂CH₂CH₂—), iso-propylene (—CH₂CH(CH₃)—), (—C(CH₃)₂CH₂CH₂—), (—C(CH₃)₂CH₂C(O)—), (—C(CH₃)₂CH₂C(O)NH—), (—CH(CH₃)CH₂—), and the like.

“Substituted alkylene” refers to an alkylene group having from 1 to 3 hydrogens replaced with substituents as described for carbons in the definition of “substituted” below.

The term “alkane” refers to alkyl group and alkylene group, as defined herein.

The term “alkylaminoalkyl”, “alkylaminoalkenyl” and “alkylaminoalkynyl” refers to the groups R′NHR″— where R′ is alkyl group as defined herein and R″ is alkylene, alkenylene or alkynylene group as defined herein.

The term “alkaryl” or “aralkyl” refers to the groups -alkylene-aryl and -substituted alkylene-aryl where alkylene, substituted alkylene and aryl are defined herein.

“Alkoxy” refers to the group —O-alkyl, wherein alkyl is as defined herein. Alkoxy includes, by way of example, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, t-butoxy, sec-butoxy, n-pentoxy, and the like. The term “alkoxy” also refers to the groups alkenyl-O—, cycloalkyl-O—, cycloalkenyl-O—, and alkynyl-O—, where alkenyl, cycloalkyl, cycloalkenyl, and alkynyl are as defined herein.

The term “substituted alkoxy” refers to the groups substituted alkyl-O—, substituted alkenyl-O—, substituted cycloalkyl-O—, substituted cycloalkenyl-O—, and substituted alkynyl-O— where substituted alkyl, substituted alkenyl, substituted cycloalkyl, substituted cycloalkenyl and substituted alkynyl are as defined herein.

The term “alkoxyamino” refers to the group —NH-alkoxy, wherein alkoxy is defined herein.

The term “haloalkoxy” refers to the groups alkyl-O— wherein one or more hydrogen atoms on the alkyl group have been substituted with a halo group and include, by way of examples, groups such as trifluoromethoxy, and the like.

The term “haloalkyl” refers to a substituted alkyl group as described above, wherein one or more hydrogen atoms on the alkyl group have been substituted with a halo group. Examples of such groups include, without limitation, fluoroalkyl groups, such as trifluoromethyl, difluoromethyl, trifluoroethyl and the like.

The term “alkylalkoxy” refers to the groups -alkylene-O-alkyl, alkylene-O-substituted alkyl, substituted alkylene-O-alkyl, and substituted alkylene-O-substituted alkyl wherein alkyl, substituted alkyl, alkylene and substituted alkylene are as defined herein.

The term “alkylthioalkoxy” refers to the group -alkylene-S-alkyl, alkylene-S-substituted alkyl, substituted alkylene-S-alkyl and substituted alkylene-S-substituted alkyl wherein alkyl, substituted alkyl, alkylene and substituted alkylene are as defined herein.

“Alkenyl” refers to straight chain or branched hydrocarbyl groups having from 2 to 6 carbon atoms and preferably 2 to 4 carbon atoms and having at least 1 and preferably from 1 to 2 sites of double bond unsaturation. This term includes, by way of example, bi-vinyl, allyl, and but-3-en-1-yl. Included within this term are the cis and trans isomers or mixtures of these isomers.

The term “substituted alkenyl” refers to an alkenyl group as defined herein having from 1 to 5 substituents, or from 1 to 3 substituents, selected from alkoxy, substituted alkoxy, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, acyl, acylamino, acyloxy, amino, substituted amino, aminoacyl, aminoacyloxy, oxyaminoacyl, azido, cyano, halogen, hydroxyl, oxo, thioketo, carboxyl, carboxylalkyl, thioaryloxy, thioheteroaryloxy, thioheterocyclooxy, thiol, thioalkoxy, substituted thioalkoxy, aryl, aryloxy, heteroaryl, heteroaryloxy, heterocyclyl, heterocyclooxy, hydroxyamino, alkoxyamino, nitro, —SO-alkyl, —SO— substituted alkyl, —SO-aryl, —SO-heteroaryl, —SO₂-alkyl, —SO₂-substituted alkyl, —SO₂-aryl and —SO₂-heteroaryl.

“Alkynyl” refers to straight or branched monovalent hydrocarbyl groups having from 2 to 6 carbon atoms and preferably 2 to 3 carbon atoms and having at least 1 and preferably from 1 to 2 sites of triple bond unsaturation. Examples of such alkynyl groups include acetylenyl (—C≡CH), and propargyl (—CH₂C≡CH).

The term “substituted alkynyl” refers to an alkynyl group as defined herein having from 1 to 5 substituents, or from 1 to 3 substituents, selected from alkoxy, substituted alkoxy, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, acyl, acylamino, acyloxy, amino, substituted amino, aminoacyl, aminoacyloxy, oxyaminoacyl, azido, cyano, halogen, hydroxyl, oxo, thioketo, carboxyl, carboxylalkyl, thioaryloxy, thioheteroaryloxy, thioheterocyclooxy, thiol, thioalkoxy, substituted thioalkoxy, aryl, aryloxy, heteroaryl, heteroaryloxy, heterocyclyl, heterocyclooxy, hydroxyamino, alkoxyamino, nitro, —SO-alkyl, —SO— substituted alkyl, —SO-aryl, —SO-heteroaryl, —SO₂-alkyl, —SO₂-substituted alkyl, —SO₂-aryl, and —SO₂-heteroaryl.

“Alkynyloxy” refers to the group —O-alkynyl, wherein alkynyl is as defined herein. Alkynyloxy includes, by way of example, ethynyloxy, propynyloxy, and the like.

“Acyl” refers to the groups H—C(O)—, alkyl-C(O)—, substituted alkyl-C(O)—, alkenyl-C(O)—, substituted alkenyl-C(O)—, alkynyl-C(O)—, substituted alkynyl-C(O)—, cycloalkyl-C(O)—, substituted cycloalkyl-C(O)—, cycloalkenyl-C(O)—, substituted cycloalkenyl-C(O)—, aryl-C(O)—, substituted aryl-C(O)—, heteroaryl-C(O)—, substituted heteroaryl-C(O)—, heterocyclyl-C(O)—, and substituted heterocyclyl-C(O)—, wherein alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, and substituted heterocyclic are as defined herein. For example, acyl includes the “acetyl” group CH₃C(O)—

“Acylamino” refers to the groups —NR²⁰C(O)alkyl, —NR²⁰C(O)substituted alkyl, NR²⁰C(O)cycloalkyl, —NR²⁰C(O)substituted cycloalkyl, —NR²⁰C(O)cycloalkenyl, —NR²⁰C(O)substituted cycloalkenyl, —NR²⁰C(O)alkenyl, —NR²⁰C(O)substituted alkenyl, —NR²⁰C(O)alkynyl, —NR²⁰C(O)substituted alkynyl, —NR²⁰C(O)aryl, —NR²⁰C(O)substituted aryl, —NR²⁰C(O)heteroaryl, —NR²⁰C(O)substituted heteroaryl, —NR²⁰C(O)heterocyclic, and —NR²⁰C(O)substituted heterocyclic, wherein R²⁰ is hydrogen or alkyl and wherein alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, and substituted heterocyclic are as defined herein.

“Aminocarbonyl” or the term “aminoacyl” refers to the group —C(O)NR²¹R²², wherein R²¹ and R²² independently are selected from the group consisting of hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, heteroaryl, substituted heteroaryl, heterocyclic, and substituted heterocyclic and where R²¹ and R²² are optionally joined together with the nitrogen bound thereto to form a heterocyclic or substituted heterocyclic group, and wherein alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, and substituted heterocyclic are as defined herein.

“Aminocarbonylamino” refers to the group —NR²¹C(O)NR²²R²³ where R²¹, R²², and R²³ are independently selected from hydrogen, alkyl, aryl or cycloalkyl, or where two R groups are joined to form a heterocyclyl group.

The term “alkoxycarbonylamino” refers to the group —NRC(O)OR where each R is independently hydrogen, alkyl, substituted alkyl, aryl, heteroaryl, or heterocyclyl wherein alkyl, substituted alkyl, aryl, heteroaryl, and heterocyclyl are as defined herein.

The term “acyloxy” refers to the groups alkyl-C(O)O—, substituted alkyl-C(O)O—, cycloalkyl-C(O)O—, substituted cycloalkyl-C(O)O—, aryl-C(O)O—, heteroaryl-C(O)O—, and heterocyclyl-C(O)O— wherein alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, aryl, heteroaryl, and heterocyclyl are as defined herein.

“Aminosulfonyl” refers to the group —SO₂NR²¹R²², wherein R²¹ and R²² independently are selected from the group consisting of hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, heteroaryl, substituted heteroaryl, heterocyclic, substituted heterocyclic and where R²¹ and R²² are optionally joined together with the nitrogen bound thereto to form a heterocyclic or substituted heterocyclic group and alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic and substituted heterocyclic are as defined herein.

“Sulfonylamino” refers to the group —NR²¹SO₂R²², wherein R²¹ and R²² independently are selected from the group consisting of hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, heteroaryl, substituted heteroaryl, heterocyclic, and substituted heterocyclic and where R²¹ and R²² are optionally joined together with the atoms bound thereto to form a heterocyclic or substituted heterocyclic group, and wherein alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, and substituted heterocyclic are as defined herein.

“Aryl” or “Ar” refers to a monovalent aromatic carbocyclic group of from 6 to 18 carbon atoms having a single ring (such as is present in a phenyl group) or a ring system having multiple condensed rings (examples of such aromatic ring systems include naphthyl, anthryl and indanyl) which condensed rings may or may not be aromatic, provided that the point of attachment is through an atom of an aromatic ring. This term includes, by way of example, phenyl and naphthyl. Unless otherwise constrained by the definition for the aryl substituent, such aryl groups can optionally be substituted with from 1 to 5 substituents, or from 1 to 3 substituents, selected from acyloxy, hydroxy, thiol, acyl, alkyl, alkoxy, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, substituted alkyl, substituted alkoxy, substituted alkenyl, substituted alkynyl, substituted cycloalkyl, substituted cycloalkenyl, amino, substituted amino, aminoacyl, acylamino, alkaryl, aryl, aryloxy, azido, carboxyl, carboxylalkyl, cyano, halogen, nitro, heteroaryl, heteroaryloxy, heterocyclyl, heterocyclooxy, aminoacyloxy, oxyacylamino, thioalkoxy, substituted thioalkoxy, thioaryloxy, thioheteroaryloxy, —SO-alkyl, —SO-substituted alkyl, —SO-aryl, —SO-heteroaryl, —SO₂-alkyl, —SO₂-substituted alkyl, —SO₂-aryl, —SO₂-heteroaryl and trihalomethyl.

“Aryloxy” refers to the group —O-aryl, wherein aryl is as defined herein, including, by way of example, phenoxy, naphthoxy, and the like, including optionally substituted aryl groups as also defined herein.

“Amino” refers to the group —NH₂.

The term “substituted amino” refers to the group —NRR where each R is independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, alkenyl, substituted alkenyl, cycloalkenyl, substituted cycloalkenyl, alkynyl, substituted alkynyl, aryl, heteroaryl, and heterocyclyl provided that at least one R is not hydrogen.

The term “azido” refers to the group —N₃.

“Carboxyl,” “carboxy” or “carboxylate” refers to —CO₂H or salts thereof.

“Carboxyl ester” or “carboxy ester” or the terms “carboxyalkyl” or “carboxylalkyl” refers to the groups —C(O)O-alkyl, —C(O)O-substituted alkyl, —C(O)O-alkenyl, —C(O)O-substituted alkenyl, —C(O)O-alkynyl, —C(O)O-substituted alkynyl, —C(O)O-aryl, —C(O)O-substituted aryl, —C(O)O-cycloalkyl, —C(O)O-substituted cycloalkyl, —C(O)O-cycloalkenyl, —C(O)O-substituted cycloalkenyl, —C(O)O-heteroaryl, —C(O)O-substituted heteroaryl, —C(O)O-heterocyclic, and —C(O)O-substituted heterocyclic, wherein alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, and substituted heterocyclic are as defined herein.

“(Carboxyl ester)oxy” or “carbonate” refers to the groups —O—C(O)O-alkyl, —O—C(O)O-substituted alkyl, —O—C(O)O-alkenyl, —O—C(O)O-substituted alkenyl, —O—C(O)O— alkynyl, —O—C(O)O-substituted alkynyl, —O—C(O)O-aryl, —O—C(O)O-substituted aryl, —O—C(O)O— cycloalkyl, —O—C(O)O-substituted cycloalkyl, —O—C(O)O-cycloalkenyl, —O—C(O)O-substituted cycloalkenyl, —O—C(O)O-heteroaryl, —O—C(O)O-substituted heteroaryl, —O—C(O)O-heterocyclic, and —O—C(O)O-substituted heterocyclic, wherein alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, and substituted heterocyclic are as defined herein.

“Cyano” or “nitrile” refers to the group —CN.

“Cycloalkyl” refers to cyclic alkyl groups of from 3 to 10 carbon atoms having single or multiple cyclic rings including fused, bridged, and spiro ring systems. Examples of suitable cycloalkyl groups include, for instance, adamantyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclooctyl and the like. Such cycloalkyl groups include, by way of example, single ring structures such as cyclopropyl, cyclobutyl, cyclopentyl, cyclooctyl, and the like, or multiple ring structures such as adamantanyl, and the like.

The term “substituted cycloalkyl” refers to cycloalkyl groups having from 1 to 5 substituents, or from 1 to 3 substituents, selected from alkyl, substituted alkyl, alkoxy, substituted alkoxy, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, acyl, acylamino, acyloxy, amino, substituted amino, aminoacyl, aminoacyloxy, oxyaminoacyl, azido, cyano, halogen, hydroxyl, oxo, thioketo, carboxyl, carboxylalkyl, thioaryloxy, thioheteroaryloxy, thioheterocyclooxy, thiol, thioalkoxy, substituted thioalkoxy, aryl, aryloxy, heteroaryl, heteroaryloxy, heterocyclyl, heterocyclooxy, hydroxyamino, alkoxyamino, nitro, —SO-alkyl, —SO-substituted alkyl, —SO-aryl, —SO-heteroaryl, —SO₂-alkyl, —SO₂-substituted alkyl, —SO₂-aryl and —SO₂-heteroaryl.

“Cycloalkenyl” refers to non-aromatic cyclic alkyl groups of from 3 to 10 carbon atoms having single or multiple rings and having at least one double bond and preferably from 1 to 2 double bonds.

The term “substituted cycloalkenyl” refers to cycloalkenyl groups having from 1 to 5 substituents, or from 1 to 3 substituents, selected from alkoxy, substituted alkoxy, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, acyl, acylamino, acyloxy, amino, substituted amino, aminoacyl, aminoacyloxy, oxyaminoacyl, azido, cyano, halogen, hydroxyl, keto, thioketo, carboxyl, carboxylalkyl, thioaryloxy, thioheteroaryloxy, thioheterocyclooxy, thiol, thioalkoxy, substituted thioalkoxy, aryl, aryloxy, heteroaryl, heteroaryloxy, heterocyclyl, heterocyclooxy, hydroxyamino, alkoxyamino, nitro, —SO-alkyl, —SO-substituted alkyl, —SO-aryl, —SO-heteroaryl, —SO₂-alkyl, —SO₂-substituted alkyl, —SO₂-aryl and —SO₂-heteroaryl.

“Cycloalkynyl” refers to non-aromatic cycloalkyl groups of from 5 to 10 carbon atoms having single or multiple rings and having at least one triple bond.

“Cycloalkoxy” refers to —O-cycloalkyl.

“Cycloalkenyloxy” refers to —O-cycloalkenyl.

“Halo” or “halogen” refers to fluoro, chloro, bromo, and iodo.

“Hydroxy” or “hydroxyl” refers to the group —OH.

“Heteroaryl” refers to an aromatic group of from 1 to 15 carbon atoms, such as from 1 to 10 carbon atoms and 1 to 10 heteroatoms selected from the group consisting of oxygen, nitrogen, and sulfur within the ring. Such heteroaryl groups can have a single ring (such as, pyridinyl (i.e., pyridyl), imidazolyl or furyl) or multiple condensed rings in a ring system (for example as in groups such as, indolizinyl, quinolinyl, benzofuran, benzimidazolyl or benzothienyl), wherein at least one ring within the ring system is aromatic and at least one ring within the ring system is aromatic, provided that the point of attachment is through an atom of an aromatic ring. In certain embodiments, the nitrogen and/or sulfur ring atom(s) of the heteroaryl group are optionally oxidized to provide for the N-oxide (N→O), sulfinyl, or sulfonyl moieties. This term includes, by way of example, pyridinyl, pyrrolyl, indolyl, thiophenyl, and furanyl. Unless otherwise constrained by the definition for the heteroaryl substituent, such heteroaryl groups can be optionally substituted with 1 to 5 substituents, or from 1 to 3 substituents, selected from acyloxy, hydroxy, thiol, acyl, alkyl, alkoxy, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, substituted alkyl, substituted alkoxy, substituted alkenyl, substituted alkynyl, substituted cycloalkyl, substituted cycloalkenyl, amino, substituted amino, aminoacyl, acylamino, alkaryl, aryl, aryloxy, azido, carboxyl, carboxylalkyl, cyano, halogen, nitro, heteroaryl, heteroaryloxy, heterocyclyl, heterocyclooxy, aminoacyloxy, oxyacylamino, thioalkoxy, substituted thioalkoxy, thioaryloxy, thioheteroaryloxy, —SO-alkyl, —SO-substituted alkyl, —SO-aryl, —SO-heteroaryl, —SO₂-alkyl, —SO₂-substituted alkyl, —SO₂-aryl and —SO₂-heteroaryl, and trihalomethyl.

The term “heteroaralkyl” refers to the groups -alkylene-heteroaryl where alkylene and heteroaryl are defined herein. This term includes, by way of example, pyridylmethyl, pyridylethyl, indolylmethyl, and the like.

“Heteroaryloxy” refers to —O-heteroaryl.

“Heterocycle,” “heterocyclic,” “heterocycloalkyl,” and “heterocyclyl” refer to a saturated or unsaturated group having a single ring or multiple condensed rings, including fused bridged and spiro ring systems, and having from 3 to 20 ring atoms, including 1 to 10 hetero atoms. These ring atoms are selected from the group consisting of nitrogen, sulfur, or oxygen, wherein, in fused ring systems, one or more of the rings can be cycloalkyl, aryl, or heteroaryl, provided that the point of attachment is through the non-aromatic ring. In certain embodiments, the nitrogen and/or sulfur atom(s) of the heterocyclic group are optionally oxidized to provide for the N-oxide, —S(O)—, or —SO₂— moieties.

Examples of heterocycles and heteroaryls include, but are not limited to, azetidine, pyrrole, imidazole, pyrazole, pyridine, pyrazine, pyrimidine, pyridazine, indolizine, isoindole, indole, dihydroindole, indazole, purine, quinolizine, isoquinoline, quinoline, phthalazine, naphthylpyridine, quinoxaline, quinazoline, cinnoline, pteridine, carbazole, carboline, phenanthridine, acridine, phenanthroline, isothiazole, phenazine, isoxazole, phenoxazine, phenothiazine, imidazolidine, imidazoline, piperidine, piperazine, indoline, phthalimide, 1,2,3,4-tetrahydroisoquinoline, 4,5,6,7-tetrahydrobenzo[b]thiophene, thiazole, thiazolidine, thiophene, benzo[b]thiophene, morpholinyl, thiomorpholinyl (also referred to as thiamorpholinyl), 1,1-dioxothiomorpholinyl, piperidinyl, pyrrolidine, tetrahydrofuranyl, and the like.

Unless otherwise constrained by the definition for the heterocyclic substituent, such heterocyclic groups can be optionally substituted with 1 to 5, or from 1 to 3 substituents, selected from alkoxy, substituted alkoxy, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, acyl, acylamino, acyloxy, amino, substituted amino, aminoacyl, aminoacyloxy, oxyaminoacyl, azido, cyano, halogen, hydroxyl, oxo, thioketo, carboxyl, carboxylalkyl, thioaryloxy, thioheteroaryloxy, thioheterocyclooxy, thiol, thioalkoxy, substituted thioalkoxy, aryl, aryloxy, heteroaryl, heteroaryloxy, heterocyclyl, heterocyclooxy, hydroxyamino, alkoxyamino, nitro, —SO-alkyl, —SO-substituted alkyl, —SO-aryl, —SO-heteroaryl, —SO₂-alkyl, —SO₂-substituted alkyl, —SO₂-aryl, —SO₂-heteroaryl, and fused heterocycle.

“Heterocyclyloxy” refers to the group —O-heterocyclyl.

The term “heterocyclylthio” refers to the group heterocyclic-S—.

The term “heterocyclene” refers to the diradical group formed from a heterocycle, as defined herein.

The term “hydroxyamino” refers to the group —NHOH.

“Nitro” refers to the group —NO₂.

“Oxo” refers to the atom (═O).

“Sulfonyl” refers to the group —SO₂-alkyl, —SO₂-substituted alkyl, —SO₂-alkenyl, —SO₂-substituted alkenyl, —SO₂-cycloalkyl, —SO₂-substituted cycloalkyl, —SO₂-cycloalkenyl, —SO₂— substituted cycloalkenyl, —SO₂-aryl, —SO₂-substituted aryl, —SO₂-heteroaryl, —SO₂-substituted heteroaryl, —SO₂-heterocyclic, and —SO₂-substituted heterocyclic, wherein alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, and substituted heterocyclic are as defined herein. Sulfonyl includes, by way of example, methyl-SO₂—, phenyl-SO₂—, and 4-methylphenyl-SO₂—.

“Sulfonyloxy” refers to the group —OSO₂-alkyl, —OSO₂-substituted alkyl, —OSO₂-alkenyl, —OSO₂-substituted alkenyl, —OSO₂-cycloalkyl, —OSO₂-substituted cycloalkyl, —OSO₂-cycloalkenyl, —OSO₂-substituted cylcoalkenyl, —OSO₂-aryl, —OSO₂-substituted aryl, —OSO₂-heteroaryl, —OSO₂-substituted heteroaryl, —OSO₂-heterocyclic, and —OSO₂ substituted heterocyclic, wherein alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic, and substituted heterocyclic are as defined herein.

The term “aminocarbonyloxy” refers to the group —OC(O)NRR where each R is independently hydrogen, alkyl, substituted alkyl, aryl, heteroaryl, or heterocyclic wherein alkyl, substituted alkyl, aryl, heteroaryl and heterocyclic are as defined herein.

“Thiol” refers to the group —SH.

“Thioxo” or the term “thioketo” refers to the atom (═S).

“Alkylthio” or the term “thioalkoxy” refers to the group —S-alkyl, wherein alkyl is as defined herein. In certain embodiments, sulfur may be oxidized to —S(O)—. The sulfoxide may exist as one or more stereoisomers.

The term “substituted thioalkoxy” refers to the group —S-substituted alkyl.

The term “thioaryloxy” refers to the group aryl-S— wherein the aryl group is as defined herein including optionally substituted aryl groups also defined herein.

The term “thioheteroaryloxy” refers to the group heteroaryl-S— wherein the heteroaryl group is as defined herein including optionally substituted aryl groups as also defined herein.

The term “thioheterocyclooxy” refers to the group heterocyclyl-S— wherein the heterocyclyl group is as defined herein including optionally substituted heterocyclyl groups as also defined herein.

The term “tosyl” refers to the group

The wavy line indicates the bond through which the tosyl group is attached to the remainder of the molecule.

In addition to the disclosure herein, the term “substituted,” when used to modify a specified group or radical, can also mean that one or more hydrogen atoms of the specified group or radical are each, independently of one another, replaced with the same or different substituent groups as defined below.

In addition to the groups disclosed with respect to the individual terms herein, substituent groups for substituting for one or more hydrogens (any two hydrogens on a single carbon can be replaced with ═O, ═NR⁷⁰, ═N—OR⁷⁰, ═N₂ or ═S) on saturated carbon atoms in the specified group or radical are, unless otherwise specified, —R⁶⁰, halo, ═O, —OR⁷⁰, —SR⁷⁰, —NR⁸⁰R⁸⁰, trihalomethyl, —CN, —OCN, —SCN, —NO, —NO₂, ═N₂, —N₃, —SO₂R⁷⁰, —SO₂O⁻M⁺, —SO₂OR⁷⁰, —OSO₂R⁷⁰, —OSO₂O⁻M⁺, —OSO₂OR⁷⁰, —P(O)(O⁻)₂(M⁺)₂, —P(O)(OR⁷⁰)O⁻M⁺, —P(O)(OR⁷⁰)₂, —C(O)R⁷⁰, —C(S)R⁷⁰, —C(NR⁷⁰)R⁷⁰, —C(O)O⁻M⁺, —C(O)OR⁷⁰, —C(S)OR⁷⁰, —C(O)NR⁸⁰R⁸⁰, —C(NR⁷⁰)NR⁸⁰R⁸⁰, —OC(O)R⁷⁰, —OC(S)R⁷⁰, —OC(O)O⁻M⁺, —OC(O)OR⁷⁰, —OC(S)OR⁷⁰, —NR⁷⁰C(O)R⁷⁰, —NR⁷⁰C(S)R⁷⁰, —NR⁷⁰CO₂ ⁻M⁺, —NR⁷⁰CO₂R⁷⁰, —NR⁷⁰C(S)OR⁷⁰, —NR⁷⁰C(O)NR⁸⁰R⁸⁰, —NR⁷⁰C(NR⁷⁰)R⁷⁰ and —NR⁷⁰C(NR⁷⁰)NR⁸⁰R⁸⁰, where R⁶⁰ is selected from the group consisting of optionally substituted alkyl, cycloalkyl, heteroalkyl, heterocycloalkylalkyl, cycloalkylalkyl, aryl, arylalkyl, heteroaryl and heteroarylalkyl, each R⁷⁰ is independently hydrogen or R⁶⁰; each R⁸⁰ is independently R⁷⁰ or alternatively, two R⁸⁰'s, taken together with the nitrogen atom to which they are bonded, form a 5-, 6- or 7-membered heterocycloalkyl which may optionally include from 1 to 4 of the same or different additional heteroatoms selected from the group consisting of O, N and S, of which N may have —H or C₁-C₃ alkyl substitution; and each M⁺ is a counter ion with a net single positive charge. Each M⁺ may independently be, for example, an alkali ion, such as K⁺, Na⁺, Li⁺; an ammonium ion, such as ⁺N(R⁶⁰)₄; or an alkaline earth ion, such as [Ca²⁺]_(0.5), [Mg²⁺]_(0.5), or [Ba²⁺]_(0.5) (“subscript 0.5 means that one of the counter ions for such divalent alkali earth ions can be an ionized form of a compound of the invention and the other a typical counter ion such as chloride, or two ionized compounds disclosed herein can serve as counter ions for such divalent alkali earth ions, or a doubly ionized compound of the invention can serve as the counter ion for such divalent alkali earth ions). As specific examples, —NR⁸⁰R⁸⁰ is meant to include —NH₂, —NH-alkyl, N-pyrrolidinyl, N-piperazinyl, 4N-methyl-piperazin-1-yl and N-morpholinyl.

In addition to the disclosure herein, substituent groups for hydrogens on unsaturated carbon atoms in “substituted” alkene, alkyne, aryl and heteroaryl groups are, unless otherwise specified, —R⁶⁰, halo, —O⁻M⁺, —OR⁷⁰, —SR⁷⁰, —S⁻M⁺, —NR⁸⁰R⁸⁰, trihalomethyl, —CF₃, —CN, —OCN, —SCN, —NO, —NO₂, —N₃, —SO₂R⁷⁰, —SO₃ ⁻M⁺, —SO₃R⁷⁰, —OSO₂R⁷⁰, —OSO₃ ⁻M⁺, —OSO₃R⁷⁰, —PO₃ ⁻²(M⁺)₂, —P(O)(OR⁷⁰)O⁻M⁺, —P(O)(OR⁷⁰)₂, —C(O)R⁷⁰, —C(S)R⁷⁰, —C(NR⁷⁰)R⁷⁰, —CO₂ ⁻M⁺, —CO₂R⁷⁰, —C(S)OR⁷⁰, —C(O)NR⁸⁰R⁸⁰, —C(NR⁷⁰)NR⁸⁰R⁸⁰, —OC(O)R⁷⁰, —OC(S)R⁷⁰, —OCO₂ ⁻M⁺, —OCO₂R⁷⁰, —OC(S)OR⁷⁰, —NR⁷⁰C(O)R⁷⁰, —NR⁷⁰C(S)R⁷⁰, —NR⁷⁰CO₂ ⁻M⁺, —NR⁷⁰CO₂R⁷⁰, —NR⁷⁰C(S)OR⁷⁰, —NR⁷⁰C(O)NR⁸⁰R⁸⁰, —NR⁷⁰C(NR⁷⁰)R⁷⁰ and —NR⁷⁰C(NR⁷⁰)NR⁸⁰R⁸⁰, where R⁶⁰, R⁷⁰, R⁸⁰ and M⁺ are as previously defined, provided that in case of substituted alkene or alkyne, the substituents are not —O⁻M⁺, —OR⁷⁰, —SR⁷⁰, or —S⁻M⁺.

In addition to the groups disclosed with respect to the individual terms herein, substituent groups for hydrogens on nitrogen atoms in “substituted” heteroalkyl and cycloheteroalkyl groups are, unless otherwise specified, —R⁶⁰, —O⁻M⁺, —OR⁷⁰, —SR⁷⁰, —S⁻M⁺, —NR⁸⁰R⁸⁰, trihalomethyl, —CF₃, —CN, —NO, —NO₂, —S(O)₂R⁷⁰, —S(O)₂O⁻M⁺, —S(O)₂OR⁷⁰, —OS(O)₂R⁷⁰, —OS(O)₂O⁻M⁺, —OS(O)₂OR⁷⁰, —P(O)(O⁻)₂(M⁺)₂, —P(O)(OR⁷⁰)O⁻M⁺, —P(O)(OR⁷⁰)(OR⁷⁰), —C(O)R⁷⁰, —C(S)R⁷⁰, —C(NR⁷⁰)R⁷⁰, —C(O)OR⁷⁰, —C(S)OR⁷⁰, —C(O)NR⁸⁰R⁸⁰, —C(NR⁷⁰)NR⁸⁰R⁸⁰, —OC(O)R⁷⁰, —OC(S)R⁷⁰, —OC(O)OR⁷⁰, —OC(S)OR⁷⁰, —NR⁷⁰C(O)R⁷⁰, —NR⁷⁰C(S)R⁷⁰, —NR⁷⁰C(O)OR⁷⁰, —NR⁷⁰C(S)OR⁷⁰, —NR⁷⁰C(O)NR⁸⁰R⁸⁰, —NR⁷⁰C(NR⁷⁰)R⁷⁰ and —NR⁷⁰C(NR⁷⁰)NR⁸⁰R⁸⁰, where R⁶⁰, R⁷⁰, R⁸⁰ and M⁺ are as previously defined.

In addition to the disclosure herein, in a certain embodiment, a group that is substituted has 1, 2, 3, or 4 substituents, 1, 2, or 3 substituents, 1 or 2 substituents, or 1 substituent.

It is understood that in all substituted groups defined above, polymers arrived at by defining substituents with further substituents to themselves (e.g., substituted aryl having a substituted aryl group as a substituent which is itself substituted with a substituted aryl group, which is further substituted with a substituted aryl group, etc.) are not intended for inclusion herein. In such cases, the maximum number of such substitutions is three. For example, serial substitutions of substituted aryl groups specifically contemplated herein are limited to substituted aryl-(substituted aryl)-substituted aryl.

Unless indicated otherwise, the nomenclature of substituents that are not explicitly defined herein are arrived at by naming the terminal portion of the functionality followed by the adjacent functionality toward the point of attachment. For example, the substituent “arylalkyloxycarbonyl” refers to the group (aryl)-(alkyl)-O—C(O)—.

As to any of the groups disclosed herein which contain one or more substituents, it is understood, of course, that such groups do not contain any substitution or substitution patterns which are sterically impractical and/or synthetically non-feasible. In addition, the subject compounds include all stereochemical isomers arising from the substitution of these compounds.

The term “pharmaceutically acceptable salt” means a salt which is acceptable for administration to a patient, such as a mammal (salts with counterions having acceptable mammalian safety for a given dosage regime). Such salts can be derived from pharmaceutically acceptable inorganic or organic bases and from pharmaceutically acceptable inorganic or organic acids. “Pharmaceutically acceptable salt” refers to pharmaceutically acceptable salts of a compound, which salts are derived from a variety of organic and inorganic counter ions well known in the art and include, by way of example only, sodium, potassium, calcium, magnesium, ammonium, tetraalkylammonium, and the like; and when the molecule contains a basic functionality, salts of organic or inorganic acids, such as hydrochloride, hydrobromide, formate, tartrate, besylate, mesylate, acetate, maleate, oxalate, and the like.

The term “salt thereof” means a compound formed when a proton of an acid is replaced by a cation, such as a metal cation or an organic cation and the like. Where applicable, the salt is a pharmaceutically acceptable salt, although this is not required for salts of intermediate compounds that are not intended for administration to a patient. By way of example, salts of the present compounds include those wherein the compound is protonated by an inorganic or organic acid to form a cation, with the conjugate base of the inorganic or organic acid as the anionic component of the salt.

“Solvate” refers to a complex formed by combination of solvent molecules with molecules or ions of the solute. The solvent can be an organic compound, an inorganic compound, or a mixture of both. Some examples of solvents include, but are not limited to, methanol, N,N-dimethylformamide, tetrahydrofuran, dimethylsulfoxide, and water. When the solvent is water, the solvate formed is a hydrate.

“Stereoisomer” and “stereoisomers” refer to compounds that have same atomic connectivity but different atomic arrangement in space. Stereoisomers include cis-trans isomers, E and Z isomers, enantiomers, and diastereomers.

“Tautomer” refers to alternate forms of a molecule that differ only in electronic bonding of atoms and/or in the position of a proton, such as enol-keto and imine-enamine tautomers, or the tautomeric forms of heteroaryl groups containing a —N═C(H)—NH— ring atom arrangement, such as pyrazoles, imidazoles, benzimidazoles, triazoles, and tetrazoles. A person of ordinary skill in the art would recognize that other tautomeric ring atom arrangements are possible.

It will be appreciated that the term “or a salt or solvate or stereoisomer thereof” is intended to include all permutations of salts, solvates and stereoisomers, such as a solvate of a pharmaceutically acceptable salt of a stereoisomer of subject compound.

“Pharmaceutically effective amount” and “therapeutically effective amount” refer to an amount of a compound sufficient to treat a specified disorder or disease or one or more of its symptoms and/or to prevent the occurrence of the disease or disorder. For example, in reference to tumorigenic proliferative disorders, a pharmaceutically or therapeutically effective amount comprises an amount sufficient to, among other things, cause the tumor to shrink or decrease the growth rate of the tumor.

“Patient” refers to human and non-human subjects, especially mammalian subjects.

The term “treating” or “treatment” as used herein means the treating or treatment of a disease or medical condition in a patient, such as a mammal (particularly a human) that includes: (a) preventing the disease or medical condition from occurring, such as, prophylactic treatment of a subject; (b) ameliorating the disease or medical condition, such as, eliminating or causing regression of the disease or medical condition in a patient; (c) suppressing the disease or medical condition, for example by, slowing or arresting the development of the disease or medical condition in a patient; or (d) alleviating a symptom of the disease or medical condition in a patient.

The terms “polypeptide,” “peptide,” and “protein” are used interchangeably herein to refer to a polymeric form of amino acids of any length. The terms “polypeptide derivative,” “peptide derivative,” and “protein derivative” can include genetically coded and non-coded amino acids, chemically or biochemically modified or derivatized amino acids, and polypeptides having modified peptide backbones.

The terms “amino acid analog,” “unnatural amino acid,” “amino acid derivative,” and the like may be used interchangeably, and include amino acid-like compounds that are similar in structure and/or overall shape to one or more amino acids commonly found in naturally occurring proteins (e.g., Ala or A, Cys or C, Asp or D, Glu or E, Phe or F, Gly or G, His or H, Ile or I, Lys or K, Leu or L, Met or M, Asn or N, Pro or P, Gln or Q, Arg or R, Ser or S, Thr or T, Val or V, Trp or W, Tyr or Y). Amino acid derivatives also include natural amino acids with modified side chains or backbones. Amino acid derivatives also include amino acid analogs with the same stereochemistry as in the naturally occurring D-form, as well as the L-form of amino acid analogs. In some instances, the amino acid derivatives share backbone structures, and/or the side chain structures of one or more natural amino acids, with difference(s) being one or more modified groups in the molecule. Such modification may include, but is not limited to, substitution of an atom (such as N) for a related atom (such as S), addition of a group (such as acyl, acetyl, methyl, or hydroxyl, etc.) or an atom (such as Cl or Br, etc.), deletion of a group, substitution of a covalent bond (single bond for double bond, etc.), or combinations thereof. For example, amino acid analogs may include N-acetyl amino acid derivatives, and the like.

Representative Embodiments

The following substituents and values are intended to provide representative examples of various aspects and embodiments. These representative values are intended to further define and illustrate such aspects and embodiments and are not intended to exclude other embodiments or to limit the scope of the present disclosure. In this regard, the representation that a particular value or substituent is preferred is not intended in any way to exclude other values or substituents from the present disclosure unless specifically indicated.

Embodiments of the present disclosure include prodrugs of compounds that activate Nrf2.

The term “prodrug” refers to a derivative of an active compound (e.g., a drug or active agent) that undergoes a transformation under the conditions of use, such as within the body, to release the active compound. Prodrugs may be, but are not necessarily, pharmacologically inactive until converted into the active drug. In some cases, prodrugs are pharmacologically inactive until converted into the active drug. In certain cases, compounds that include a progroup may facilitate removal of the progroup at a desired site of action for the pharmaceutically active form of the compound, or after a desired amount of time after administration of the compound (e.g., delayed release formulations, controlled release formulations, and the like). A wide variety of progroups, as well as the resultant promoieties, suitable for masking functional groups in the active drugs to yield prodrugs may be used. For example, a hydroxyl functional group can be masked as a sulfonate, ester or carbonate promoiety, which can be hydrolyzed in vivo to provide the hydroxyl group. An amino functional group can be masked as an amide, carbamate, imine, urea, phosphenyl, phosphoryl or sulfenyl promoiety, which can be hydrolyzed in vivo to provide the amino group. A carboxyl group can be masked as an ester (including silyl esters and thioesters), amide or hydrazide promoiety, which can be hydrolyzed in vivo to provide the carboxyl group. Other specific examples of suitable progroups and their respective promoieties will be apparent to those of skill in the art.

In some instances, prodrugs may be obtained by masking a functional group in the drug believed to be in part required for activity with a progroup to form a promoiety which undergoes a transformation, such as cleavage, under the specified conditions of use to release the active drug. The cleavage of the promoiety can proceed spontaneously, such as by way of a hydrolysis reaction, or it can be catalyzed or induced by another agent, such as by an enzyme, by light, by acid, or by a change of or exposure to a physical or environmental parameter, such as a change of temperature. The agent can be endogenous to the conditions of use, such as an enzyme present in the cells to which the prodrug is administered or the acidic conditions of the stomach, or it can be supplied exogenously. For example, in certain cases, compounds that include a progroup may facilitate an increase in gastrointestinal permeability, an increase in gastrointestinal absorption, and/or an increase in solubility of the compound.

In certain embodiments, a prodrug can include a conjugate of two or more moieties. For example, a prodrug can include a conjugate of two (or more) active agents, such as a conjugate of an active agent (e.g., a Nrf2 activating compound) to a second moiety (e.g., a second active agent, an antioxidant, an amino acid, an amino acid derivative, a peptide, or a peptide derivative). The second moiety can have a desired biological activity in the subject to which the prodrug is administered. As such, a prodrug that is a conjugate of two (or more) active agents can undergo a transformation, such as a cleavage or hydrolysis reaction, at a desired site of action such that two (or more) pharmaceutically active agents are released at the site of action. In certain embodiments, prodrugs of the present disclosure are conjugates of two active agents that may be used for synergistic treatment of a particular targeted disease or condition. For example, prodrugs of the present disclosure may include a conjugate of an Nrf2 activating compound and a second moiety. The second moiety may be an active agent that also has a desired biological activity, such as a biological activity useful for the treatment of a disease or condition that is also treated with the Nrf2 activating compound released from the same prodrug as the second moiety.

Without being bound to any particular mechanistic theory, some embodiments of prodrugs of the present disclosure are adducts, such as a Michael addition adduct. Under the conditions of use, such as when administered to a subject, the Michael addition adduct prodrug may undergo a retro-Michael reaction to release the Michael acceptor compound and the Michael donor compound. The Michael adduct prodrug can be an adduct of an active agent (e.g., a Nrf2 activating compound) and a second moiety. As described above, the second moiety can be a moiety such as a second active agent, an antioxidant, an amino acid, an amino acid derivative, a peptide, or a peptide derivative, where the second moiety has a desired biological activity in the subject to which the prodrug is administered. For example, as indicated above, the second moiety may be an active agent that also has a desired biological activity, such as a biological activity useful for the treatment of a disease or condition that is also treated with the Nrf2 activating compound released from the same prodrug as the second moiety. In certain embodiments, prodrugs of the present disclosure release two active agents, such as a Nrf2 activating compound and a second moiety, where the two active agents may be used for synergistic treatment of a particular targeted disease or condition.

As described above, the compounds released by the prodrug at the desired site of action can include a Nrf2 activating compound. By “activating” is meant that a compound selectively increases the activity of a particular target. In some cases, an activating compound may also be referred to as an “agonist”. For example, in some embodiments, a subject Nrf2 activating compound selectively increases the activity of Nrf2, as compared to the activity of Nrf2 in the absence of the compound. For example, in some embodiments, a subject Nrf2 activating compound increases the activity of Nrf2 by 5% or more, e.g., by 10% or more, 15% or more, 20% or more, 25% or more, 30% or more, 35% or more, 40% or more, 45% or more, 50% or more, 55% or more, 60% or more, 65% or more, 70% or more, 75% or more, 80% or more, 85% or more, 90% or more, 95% or more, or 100% or more, as compared to the activity of Nrf2 in the absence of the compound.

Additional description of the types of Nrf2 activating compounds that find use in the prodrugs disclosed herein is found in U.S. Pat. Nos. 9,475,781; 9,845,307; and 9,845,311, the disclosures of which are incorporated herein by reference.

The prodrugs of the present disclosure include compounds of the formulae shown below. Pharmaceutical compositions of the prodrugs and methods involving the prodrugs of the present disclosure also use compounds of the following formulae.

Formula I

Embodiments of the presently disclosed compounds are represented by the following formula (I):

wherein:

R² is selected from the group consisting of sulfonyl, carboxyl, carboxyl ester, and aminoacyl;

R³ is selected from the group consisting of an active agent, an antioxidant, an amino acid, an amino acid derivative, a peptide, and a peptide derivative;

R⁴ is selected from the group consisting of hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, heteroaryl, and substituted heteroaryl;

X¹ and X² are each independently selected from N and CH, wherein at least one of X¹ and X² is N; and

n is an integer from 1 to 6,

or a salt or a stereoisomer thereof.

In certain embodiments, R² is sulfonyl, carboxyl, carboxyl ester, or aminoacyl. In certain embodiments, R² is sulfonyl. In certain embodiments, R² is carboxyl. In certain embodiments, R² is carboxyl ester. In certain embodiments, R² is aminoacyl. Additional description regarding the R² substituent is provided in the sections below.

In certain embodiments, R³ is an active agent, an antioxidant, an amino acid, an amino acid derivative, a peptide, or a peptide derivative. In certain embodiments, R³ is an active agent. In certain embodiments, R³ is an antioxidant. In certain embodiments, R³ is an amino acid. In certain embodiments, R³ is an amino acid derivative. In certain embodiments, R³ is a peptide. In certain embodiments, R³ is a peptide derivative. Additional description regarding the R³ substituent is provided in the sections below.

In certain embodiments, X¹ and X² are each independently selected from N and CH, where at least one of X¹ and X² is N. In some instances, X¹ is N and X² is N. In some instances, X¹ is N and X² is CH. In some instances, X¹ is CH and X² is N.

In certain embodiments, n is an integer from 1 to 6. In certain embodiments, n is 1. In certain embodiments, n is 2. In certain embodiments, n is 3. In certain embodiments, n is 4. In certain embodiments, n is 5. In certain embodiments, n is 6.

Embodiments of the R⁴ substituent are described in more detail below.

Formula Ia & Formula Ib

In certain embodiments, the compounds of formula (I) include compounds where X¹ is N and X² is N. As such, compounds of the present disclosure may be represented by the following formula (Ia):

wherein

R² is selected from the group consisting of sulfonyl, carboxyl, carboxyl ester, and aminoacyl;

R³ is selected from the group consisting of an active agent, an antioxidant, an amino acid, an amino acid derivative, a peptide, and a peptide derivative;

R⁴ is selected from the group consisting of hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, heteroaryl, and substituted heteroaryl; and

n is an integer from 1 to 6,

or a salt or a stereoisomer thereof.

In certain embodiments, R² is sulfonyl, carboxyl, carboxyl ester, or aminoacyl. In certain embodiments, R² is sulfonyl. In certain embodiments, R² is carboxyl. In certain embodiments, R² is carboxyl ester. In certain embodiments, R² is aminoacyl. Additional description regarding the R² substituent is provided in the sections below.

In certain embodiments, R³ is an active agent, an antioxidant, an amino acid, an amino acid derivative, a peptide, or a peptide derivative. In certain embodiments, R³ is an active agent. In certain embodiments, R³ is an antioxidant. In certain embodiments, R³ is an amino acid. In certain embodiments, R³ is an amino acid derivative. In certain embodiments, R³ is a peptide. In certain embodiments, R³ is a peptide derivative. Additional description regarding the R³ substituent is provided in the sections below.

In certain embodiments, n is an integer from 1 to 6. In certain embodiments, n is 1. In certain embodiments, n is 2. In certain embodiments, n is 3. In certain embodiments, n is 4. In certain embodiments, n is 5. In certain embodiments, n is 6.

Embodiments of the R⁴ substituent are described in more detail below.

In certain embodiments, the compounds of formula (I) include compounds where X¹ is N and X² is CH. As such, compounds of the present disclosure may be represented by the following formula (Ib):

wherein

R² is selected from the group consisting of sulfonyl, carboxyl, carboxyl ester, and aminoacyl;

R³ is selected from the group consisting of an active agent, an antioxidant, an amino acid, an amino acid derivative, a peptide, and a peptide derivative;

R⁴ is selected from the group consisting of hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, heteroaryl, and substituted heteroaryl; and

n is an integer from 1 to 6,

or a salt or a stereoisomer thereof.

In certain embodiments, R² is sulfonyl, carboxyl, carboxyl ester, or aminoacyl. In certain embodiments, R² is sulfonyl. In certain embodiments, R² is carboxyl. In certain embodiments, R² is carboxyl ester. In certain embodiments, R² is aminoacyl. Additional description regarding the R² substituent is provided in the sections below.

In certain embodiments, R³ is an active agent, an antioxidant, an amino acid, an amino acid derivative, a peptide, or a peptide derivative. In certain embodiments, R³ is an active agent. In certain embodiments, R³ is an antioxidant. In certain embodiments, R³ is an amino acid. In certain embodiments, R³ is an amino acid derivative. In certain embodiments, R³ is a peptide. In certain embodiments, R³ is a peptide derivative. Additional description regarding the R³ substituent is provided in the sections below.

In certain embodiments, n is an integer from 1 to 6. In certain embodiments, n is 1. In certain embodiments, n is 2. In certain embodiments, n is 3. In certain embodiments, n is 4. In certain embodiments, n is 5. In certain embodiments, n is 6.

Embodiments of the R⁴ substituent are described in more detail below.

In the description of the various substituents of the chemical formulae described herein, references to formula (I) are intended to include formula (Ia) and formula (Ib) as described herein where applicable.

Formula II

In certain embodiments of formula (I), R² is sulfonyl. As such, embodiments of the presently disclosed compounds can be represented by the following formula (II):

wherein:

R³ is selected from the group consisting of an active agent, an antioxidant, an amino acid, an amino acid derivative, a peptide, and a peptide derivative;

R⁴ is selected from the group consisting of hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, heteroaryl, and substituted heteroaryl;

R⁵ is selected from the group consisting of alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, heteroaryl, and substituted heteroaryl;

X¹ and X² are each independently selected from N and CH, wherein at least one of X¹ and X² is N; and

n is an integer from 1 to 6,

or a salt or a stereoisomer thereof.

In certain embodiments, R³ is an active agent, an antioxidant, an amino acid, an amino acid derivative, a peptide, or a peptide derivative. In certain embodiments, R³ is an active agent. In certain embodiments, R³ is an antioxidant. In certain embodiments, R³ is an amino acid. In certain embodiments, R³ is an amino acid derivative. In certain embodiments, R³ is a peptide. In certain embodiments, R³ is a peptide derivative. Additional description regarding the R³ substituent is provided in the sections below.

In certain embodiments, X¹ and X² are each independently selected from N and CH, where at least one of X¹ and X² is N. In some instances, X¹ is N and X² is N. In some instances, X¹ is N and X² is CH. In some instances, X¹ is CH and X² is N.

In certain embodiments, n is an integer from 1 to 6. In certain embodiments, n is 1. In certain embodiments, n is 2. In certain embodiments, n is 3. In certain embodiments, n is 4. In certain embodiments, n is 5. In certain embodiments, n is 6.

Embodiments of the R⁴ substituent are described in more detail below.

Embodiments of the R⁵ substituent are described in more detail below.

Formula IIa & Formula IIb

In certain embodiments, the compounds of formula (II) include compounds where X¹ is N and X² is N. As such, compounds of the present disclosure may be represented by the following formula (IIa):

wherein

R³ is selected from the group consisting of an active agent, an antioxidant, an amino acid, an amino acid derivative, a peptide, and a peptide derivative;

R⁴ is selected from the group consisting of hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, heteroaryl, and substituted heteroaryl; and

R⁵ is selected from the group consisting of alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, heteroaryl, and substituted heteroaryl;

n is an integer from 1 to 6,

or a salt or a stereoisomer thereof.

In certain embodiments, R³ is an active agent, an antioxidant, an amino acid, an amino acid derivative, a peptide, or a peptide derivative. In certain embodiments, R³ is an active agent. In certain embodiments, R³ is an antioxidant. In certain embodiments, R³ is an amino acid. In certain embodiments, R³ is an amino acid derivative. In certain embodiments, R³ is a peptide. In certain embodiments, R³ is a peptide derivative. Additional description regarding the R³ substituent is provided in the sections below.

In certain embodiments, n is an integer from 1 to 6. In certain embodiments, n is 1. In certain embodiments, n is 2. In certain embodiments, n is 3. In certain embodiments, n is 4. In certain embodiments, n is 5. In certain embodiments, n is 6.

Embodiments of the R⁴ substituent are described in more detail below.

Embodiments of the R⁵ substituent are described in more detail below.

In certain embodiments, the compounds of formula (II) include compounds where X¹ is N and X² is CH. As such, compounds of the present disclosure may be represented by the following formula (IIb):

wherein

R³ is selected from the group consisting of an active agent, an antioxidant, an amino acid, an amino acid derivative, a peptide, and a peptide derivative;

R⁴ is selected from the group consisting of hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, heteroaryl, and substituted heteroaryl; and

R⁵ is selected from the group consisting of alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, heteroaryl, and substituted heteroaryl;

n is an integer from 1 to 6,

or a salt or a stereoisomer thereof.

In certain embodiments, R³ is an active agent, an antioxidant, an amino acid, an amino acid derivative, a peptide, or a peptide derivative. In certain embodiments, R³ is an active agent. In certain embodiments, R³ is an antioxidant. In certain embodiments, R³ is an amino acid. In certain embodiments, R³ is an amino acid derivative. In certain embodiments, R³ is a peptide. In certain embodiments, R³ is a peptide derivative. Additional description regarding the R³ substituent is provided in the sections below.

In certain embodiments, n is an integer from 1 to 6. In certain embodiments, n is 1. In certain embodiments, n is 2. In certain embodiments, n is 3. In certain embodiments, n is 4. In certain embodiments, n is 5. In certain embodiments, n is 6.

Embodiments of the R⁴ substituent are described in more detail below.

Embodiments of the R⁵ substituent are described in more detail below.

In the description of the various substituents of the chemical formulae described herein, references to formula (II) are intended to include formula (IIa) and formula (IIb) as described herein where applicable.

Additional Description of the Subject Compounds

Where applicable, the description of the subject compounds in this section applies to compounds of formulae (I), (Ia), (Ib), (II), (IIa), and (IIb).

In certain embodiments, R² is sulfonyl. For example, R² may be selected from alkyl-SO₂—, substituted alkyl-SO₂—, alkenyl-SO₂—, substituted alkenyl-SO₂—, cycloalkyl-SO₂—, substituted cycloalkyl-SO₂—, heterocycloalkyl-SO₂—, substituted heterocycloalkyl-SO₂—, aryl-SO₂—, substituted aryl-SO₂—, heteroaryl-SO₂—, and substituted heteroaryl-SO₂—. In some embodiments, R² is alkyl-SO₂— or substituted alkyl-SO₂—. In some embodiments, R² is alkenyl-SO₂— or substituted alkenyl-SO₂—. In some embodiments, R² is cycloalkyl-SO₂— or substituted cycloalkyl-SO₂—. In some embodiments, R² is heterocycloalkyl-SO₂— or substituted heterocycloalkyl-SO₂—. In some embodiments, R² is aryl-SO₂— or substituted aryl-SO₂—. In some embodiments, R² is heteroaryl-SO₂— or substituted heteroaryl-SO₂—.

For example, in embodiments where R² is alkyl-SO₂—, R² may be C₁₋₆ alkyl-SO₂—, or C₁₋₅ alkyl-SO₂—, or C₁₋₄ alkyl-SO₂—, or C₁₋₃ alkyl-SO₂—, or C₁₋₂ alkyl-SO₂—. In some instances, R² is methyl-SO₂—. In other embodiments, R² may be substituted alkyl-SO₂—, such as for example substituted C₁₋₆ alkyl-SO₂—, or substituted C₁₋₅ alkyl-SO₂—, or substituted C₁₋₄ alkyl-SO₂—, or substituted C₁₋₃ alkyl-SO₂—, or substituted C₁₋₂ alkyl-SO₂—.

In certain embodiments, R² is aryl-SO₂— or substituted aryl-SO₂—. For example, in embodiments where R² is aryl-SO₂—, R² may be phenyl-SO₂—.

In other embodiments, R² is substituted aryl-SO₂—, such as for example substituted phenyl-SO₂—. In certain embodiments, the substituent on the aryl group in a substituted aryl-SO₂— is C₁₋₆ alkyl, or C₁₋₅ alkyl, or C₁₋₄ alkyl, or C₁₋₃ alkyl, or C₁₋₂ alkyl. In certain embodiments, the substituent on the aryl group in the substituted aryl-SO₂— is methyl. For example, the substituted aryl-SO₂— may be a substituted phenyl-SO₂—, such as where the substituent on the phenyl group in the substituted phenyl-SO₂— is C₁₋₆ alkyl, or C₁₋₅ alkyl, or C₁₋₄ alkyl, or C₁₋₃ alkyl, or C₁₋₂ alkyl. In certain embodiments, the substituent on the phenyl group in the substituted phenyl-SO₂— is methyl. For example, R² may be 2-methylphenyl-SO₂— (i.e., o-tolylsulfonyl), 3-methylphenyl-SO₂— (i.e., m-tolylsulfonyl), or 4-methylphenyl-SO₂— (i.e., tosyl). In certain embodiments, R² is 4-methylphenyl-SO₂— (i.e., tosyl).

In certain embodiments, the substituent on the aryl group in a substituted aryl-SO₂— is a halogen. The substituted aryl-SO₂— may include one or more halogen substituents, such as 5, 4, 3, 2, or 1 halogen substituents. In embodiments of the substituted aryl-SO₂— that include more than one halogen substituent, each halogen substituent is independently selected from fluoro, chloro, bromo, and iodo. In some instances, the substituted aryl-SO₂— includes one halogen substituent. The halogen substituent may be selected from fluoro, chloro, bromo, and iodo. In some instances, the halogen substituent is fluoro. For example, the substituted aryl-SO₂— may be a substituted phenyl-SO₂—, such as where the substituent on the phenyl group in the substituted phenyl-SO₂— is a halogen. As described above, the substituted phenyl-SO₂— may include one or more halogen substituents, such as 5, 4, 3, 2, or 1 halogen substituents. In embodiments of the substituted phenyl-SO₂— that include more than one halogen substituent, each halogen substituent is independently selected from fluoro, chloro, bromo, and iodo. In some instances, the substituted phenyl-SO₂— includes one halogen substituent. The halogen substituent may be selected from fluoro, chloro, bromo, and iodo. In some instances, the halogen substituent is fluoro. For example, R² may be 2-fluorophenyl-SO₂—, 3-fluorophenyl-SO₂—, or 4-fluorophenyl-SO₂—. In certain embodiments, R² is 4-fluorophenyl-SO₂—.

In certain embodiments, R² is carboxyl (e.g., —COOH).

In certain embodiments, R² is carboxyl ester. For example, R² can be carboxyl ester represented by the group —C(O)OR⁶. In certain embodiments, R⁶ is C₁₋₆ alkyl. In certain embodiments, R⁶ is methyl. In certain embodiments, R⁶ is ethyl. In certain embodiments, R⁶ is propyl. In certain embodiments, R⁶ is butyl. In certain embodiments, R⁶ is pentyl. In certain embodiments, R⁶ is hexyl. The C₁₋₆ alkyl may be unbranched or branched. For example, R⁶ may be propyl, such as n-propyl or iso-propyl. For example, R⁶ may be butyl, such as n-butyl, sec-butyl (1-methylpropyl), iso-butyl (2-methylpropyl) or tert-butyl (1,1-dimethylethyl).

In certain embodiments, R² is aminoacyl. For example, R² may be represented by the group —C(O)NR²¹R²², where each R²¹ and R²² is independently selected from hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, and substituted heteroaryl, and where R²¹ and R²² are optionally joined together with the nitrogen bound thereto to form a heterocycloalkyl, substituted heterocycloalkyl, heteroaryl, or substituted heteroaryl group.

In certain embodiments, R² is —C(O)NR²¹R²², where R²¹ is selected from hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, and substituted heteroaryl. In certain embodiments, R²¹ is hydrogen. In certain embodiments, R²¹ is alkyl or substituted alkyl. For example, R²¹ may be alkyl, such as C₁₋₆ alkyl, or C₁₋₅ alkyl, or C₁₋₄ alkyl, or C₁₋₃ alkyl, or C₁₋₂ alkyl. In some cases, R²¹ is methyl. In certain embodiments, R²¹ is alkenyl or substituted alkenyl. In certain embodiments, R²¹ is alkynyl or substituted alkynyl. In certain embodiments, R²¹ is cycloalkyl or substituted cycloalkyl. In certain embodiments, R²¹ is cycloalkenyl or substituted cycloalkenyl. In certain embodiments, R²¹ is heterocycloalkyl or substituted heterocycloalkyl. In certain embodiments, R²¹ is aryl or substituted aryl. In certain embodiments, R²¹ is heteroaryl or substituted heteroaryl.

In certain embodiments, R² is —C(O)NR²¹R²², where R²² is selected from hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, and substituted heteroaryl. In certain embodiments, R²² is hydrogen. In certain embodiments, R²² is alkyl or substituted alkyl. For example, R²² may be alkyl, such as C₁₋₆ alkyl, or C₁₋₅ alkyl, or C₁₋₄ alkyl, or C₁₋₃ alkyl, or C₁₋₂ alkyl. In some cases, R²² is methyl. In certain embodiments, R²² is alkenyl or substituted alkenyl. In certain embodiments, R²² is alkynyl or substituted alkynyl. In certain embodiments, R²² is cycloalkyl or substituted cycloalkyl. In certain embodiments, R²² is cycloalkenyl or substituted cycloalkenyl. In certain embodiments, R²² is heterocycloalkyl or substituted heterocycloalkyl. In certain embodiments, R²² is aryl or substituted aryl. In certain embodiments, R²² is heteroaryl or substituted heteroaryl.

In certain embodiments, R²¹ and R²² are the same. For example, in embodiments where R²¹ and R²² are the same, R²¹ may be methyl and R²² maybe methyl. In other embodiments, R²¹ and R²² are different.

In certain embodiments, R² is —C(O)NR²¹R²², where R²¹ and R²² are joined together with the nitrogen bound thereto to form a heterocycloalkyl, substituted heterocycloalkyl, heteroaryl, or substituted heteroaryl group. In certain embodiments, R²¹ and R²² are joined together with the nitrogen bound thereto to form a heterocycloalkyl or substituted heterocycloalkyl. For example, R²¹ and R²² may be joined together with the nitrogen bound thereto to form a pyrrolidinyl. In some cases, R²¹ and R²² are joined together with the nitrogen bound thereto to form a pyrrolidinyl, where the nitrogen of the pyrrolidinyl is attached to the adjacent —C(O)— of R² (i.e., a pyrrolidin-1-yl substituent). In certain embodiments, R²¹ and R²² are joined together with the nitrogen bound thereto to form a heteroaryl or substituted heteroaryl group.

In certain embodiments, R³ is an active agent, an antioxidant, an amino acid, an amino acid derivative, a peptide, or a peptide derivative. In certain embodiments, R³ is an active agent. Any number of active agents are suitable for use, or can be modified to be rendered suitable for use in the compounds, prodrugs, conjugates and adducts described herein. For example, the active agent can be an active agent suitable for use in the treatment of a disease or condition that is also amenable to treatment using an Nrf2 activating compound. For instance, the active agent can be an active agent suitable for use in the treatment of a disease or disorder caused by oxidative stress (e.g., oxidative stress caused by injury or an autoimmune or an inflammatory disease or disorder), in a subject in need of treatment. In certain instances, the active agent is an active agent suitable for use in the treatment of a disease or disorder that is amenable to treatment by an antioxidant, such as by one or more antioxidant proteins, peptides, peptide derivatives, amino acids, or amino acid derivatives.

In certain instances, the active agent is an active agent suitable for use in the treatment of a disease or disorder, where the disease or disorder is an autoimmune or an inflammatory disease or disorder. In certain instances, the active agent is an active agent suitable for use in the treatment of a disease or disorder, where the disease or disorder is psoriasis, such as plaque psoriasis. In certain instances, the active agent is an active agent suitable for use in the treatment of a disease or disorder, where the disease or disorder is multiple sclerosis. Other diseases that can be treated with the active agents disclosed herein include pulmonary arterial hypertension (PAH), non-alcoholic and alcoholic steatohepatitis, traumatic brain injury, radiation exposure and exposure to toxic chemicals such as cyanide.

Examples of active agents suitable for use in the compounds, prodrugs, conjugates and adducts described herein include, but are not limited to, glutathione (GSH), vitamin D₃, etc. For example, glutathione may include a thiol group, where the thiol group is used to form a thioether linkage between glutathione and an Nrf2 activating compound to produce a prodrug as described herein. As described herein, the prodrug can undergo an in vivo transformation when administered to a subject, such as a cleavage reaction, at a desired site of action such that the Nrf2 activating compound and the active agent (e.g., glutathione) are released at the site of action.

In certain embodiments, R³ is an antioxidant, such as but not limited to glutathione, ascorbic acid, etc.

In certain embodiments, R³ is an amino acid or an amino acid derivative. The amino acid or amino acid derivative can include any naturally occurring amino acid or derivative thereof. For example, natural amino acids include any of the commonly occurring amino acids, such as Ala or A, Cys or C, Asp or D, Glu or E, Phe or F, Gly or G, His or H, Ile or I, Lys or K, Leu or L, Met or M, Asn or N, Pro or P, Gln or Q, Arg or R, Ser or S, Thr or T, Val or V, Trp or W, Tyr or Y. In certain embodiments, the amino acid is cysteine. For example, cysteine may include a thiol group, where the thiol group is used to form a thioether linkage between cysteine and an Nrf2 activating compound to produce a prodrug as described herein. As described herein, the prodrug can undergo an in vivo transformation when administered to a subject, such as a cleavage reaction, at a desired site of action such that the Nrf2 activating compound and the amino acid (e.g., cysteine) are released at the site of action.

In some instances, amino acid derivatives include unnatural amino acids with modified side chains or backbones. For example, the amino acid derivative can be a derivative of cysteine, where the natural amino acid cysteine has been modified by one or more modified groups in the molecule. In some instances, the modified cysteine derivative includes the addition of one or more groups (such as acyl, acetyl, methyl, etc.). For example, the modified cysteine derivative may include an N-acetyl group, and/or the carboxyl end of the cysteine residue may be modified to be a carboxyl ester, such as a methyl ester. Amino acid derivatives also include amino acid analogs with the same stereochemistry as in the naturally occurring D-form, as well as the L-form of amino acid analogs.

In certain embodiments, R³ is a peptide or a peptide derivative. Any number of peptides or peptide derivatives are suitable for use, or can be modified to be rendered suitable for use in the compounds, prodrugs, conjugates and adducts described herein. For example, the peptide or peptide derivative can be a peptide or peptide derivative suitable for use in the treatment of a disease or condition that is also amenable to treatment using an Nrf2 activating compound. For instance, the peptide or peptide derivative can be a peptide or peptide derivative suitable for use in the treatment of a disease or disorder caused by oxidative stress (e.g., oxidative stress caused by injury or an autoimmune or an inflammatory disease or disorder), in a subject in need of treatment. In certain instances, the peptide or peptide derivative is a peptide or peptide derivative suitable for use in the treatment of a disease or disorder that is amenable to treatment by an antioxidant, such as by one or more antioxidant peptides or peptide derivatives.

In certain embodiments, R⁴ is selected from hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, heteroaryl, and substituted heteroaryl.

In certain embodiments, R⁴ is hydrogen. In certain embodiments, R⁴ is alkyl or substituted alkyl. In certain embodiments, R⁴ is alkyl, such as C₁₋₆ alkyl, or C₁₋₅ alkyl, or C₁₋₄ alkyl, or C₁₋₃ alkyl, or C₁₋₂ alkyl. In certain embodiments, R⁴ is methyl. In certain embodiments, R⁴ is ethyl. In certain embodiments, R⁴ is substituted alkyl, such as substituted C₁₋₆ alkyl, or substituted C₁₋₅ alkyl, or substituted C₁₋₄ alkyl, or substituted C₁₋₃ alkyl, or substituted C₁₋₂ alkyl. In certain embodiments, the substituent on the alkyl group in the substituted alkyl is cycloalkyl, substituted cycloalkyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, heteroaryl, or substituted heteroaryl. For example, the substituent on the alkyl group in the substituted alkyl may be cycloalkyl or substituted cycloalkyl. In some instances, the substituent on the alkyl group in the substituted alkyl is heterocyclyl or substituted heterocyclyl. In some instances, the substituent on the alkyl group in the substituted alkyl is aryl or substituted aryl. In some instances, the substituent on the alkyl group in the substituted alkyl is heteroaryl or substituted heteroaryl.

In certain embodiments, R⁴ is substituted alkyl, such as substituted C₁₋₆ alkyl. In certain embodiments, R⁴ is substituted methyl. In certain embodiments, R⁴ is substituted ethyl. In certain embodiments, R⁴ is substituted propyl. In certain embodiments, R⁴ is substituted butyl. In certain embodiments, R⁴ is substituted pentyl. In certain embodiments, R⁴ is substituted hexyl. Substituents on R⁴ include, but are not limited to, halogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, alkoxy, substituted alkoxy, hydroxyl, carboxyl, carboxyl ester, amino, substituted amino, acyl, aminoacyl, acylamino, thioalkoxy, sulfonyl, aminosulfonyl, sulfonylamino, cycloalkyl, substituted cycloalkyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, heteroaryl, and substituted heteroaryl. For example, R⁴ may be a substituted alkyl (e.g., substituted C₁₋₆ alkyl), substituted with a hydroxyl. In some instances, R⁴ is a substituted alkyl (e.g., substituted C₁₋₆ alkyl), substituted with alkoxy or substituted alkoxy, such as a C₁₋₆ alkoxy or a C₁₋₆ substituted alkoxy. In some instances, R⁴ is a substituted alkyl (e.g., substituted C₁₋₆ alkyl), substituted with amino or substituted amino. In some instances, R⁴ is a substituted alkyl (e.g., substituted C₁₋₆ alkyl), substituted with carboxyl or carboxyl ester. In some instances, R⁴ is a substituted alkyl (e.g., substituted C₁₋₆ alkyl), substituted with aminoacyl or acylamino. In some instances, R⁴ is a substituted alkyl (e.g., substituted C₁₋₆ alkyl), substituted with thioalkoxy or sulfonyl. In some instances, R⁴ is a substituted alkyl (e.g., substituted C₁₋₆ alkyl), substituted with cycloalkyl or substituted cycloalkyl, such as, for example, C₃₋₈ cycloalkyl or C₃₋₈ substituted cycloalkyl, or C₃₋₆ cycloalkyl or C₃₋₆ substituted cycloalkyl, or C₃₋₅ cycloalkyl or C₃₋₅ substituted cycloalkyl, or C₃₋₄ cycloalkyl or C₃₋₄ substituted cycloalkyl. In some instances, R⁴ is a substituted alkyl (e.g., substituted C₁₋₆ alkyl), substituted with heterocyclyl or substituted heterocyclyl, such as, for example, C₃₋₈ heterocyclyl or C₃₋₈ substituted heterocyclyl, or C₃₋₆ heterocyclyl or C₃₋₆ substituted heterocyclyl, or C₃₋₅ heterocyclyl or C₃₋₅ substituted heterocyclyl, or C₃₋₄ heterocyclyl or C₃₋₄ substituted heterocyclyl. In some instances, R⁴ is a substituted alkyl (e.g., substituted C₁₋₆ alkyl), substituted with aryl or substituted aryl, such as, for example, C₃₋₆ aryl or C₃₋₆ substituted aryl, such as phenyl or substituted phenyl. In some instances, R⁴ is a substituted alkyl (e.g., substituted C₁₋₆ alkyl), substituted with heteroaryl or substituted heteroaryl, such as, for example, C₃₋₆ heteroaryl or C₃₋₆ substituted heteroaryl, such as pyridyl or substituted pyridyl (e.g., 3-pyridyl or substituted 3-pyridyl). Combinations of the above substituents on R⁴ are also included. Any of the R⁴ groups described herein may be included in the compounds of the present disclosure.

For example, the substituted alkyl may be a substituted methyl group, where the substituent on the methyl group is cycloalkyl, substituted cycloalkyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, heteroaryl, or substituted heteroaryl. In some instances, the substituent on the methyl group is cycloalkyl or substituted cycloalkyl. In some instances, the substituent on the methyl group is heterocyclyl or substituted heterocyclyl. In some instances, the substituent on the methyl group is aryl or substituted aryl. For example, the substituent on the methyl group may be an aryl, such as phenyl (i.e., R⁴ is benzyl). In some instances, the substituent on the methyl group is heteroaryl or substituted heteroaryl, such as pyridyl or substituted pyridyl (e.g., 3-pyridyl or substituted 3-pyridyl).

In certain embodiments, R⁴ is alkenyl or substituted alkenyl. In certain embodiments, R⁴ is alkynyl or substituted alkynyl.

In certain embodiments, R⁴ is cycloalkyl or substituted cycloalkyl. In certain embodiments, R⁴ is cyclohexyl or substituted cyclohexyl. In certain embodiments, R⁴ is cyclopentyl or substituted cyclopentyl. In certain embodiments, R⁴ is cyclobutyl or substituted cyclobutyl. In certain embodiments, R⁴ is cyclopropyl or substituted cyclopropyl. In certain embodiments, R⁴ is heterocyclyl or substituted heterocyclyl. In certain embodiments, R⁴ is 4-tetrahydropyranyl or substituted 4-tetrahydropyranyl.

In certain embodiments, R⁴ is aryl or substituted aryl. In certain embodiments, R⁴ is phenyl or substituted phenyl. In certain embodiments, R⁴ is phenyl. In certain embodiments, R⁴ is substituted phenyl. In certain embodiments, R⁴ is heteroaryl or substituted heteroaryl. In certain embodiments, R⁴ is heteroaryl. In certain embodiments, R⁴ is substituted heteroaryl. In certain embodiments, R⁴ is pyridyl or substituted pyridyl. In certain embodiments, R⁴ is 2-pyridyl, 3-pyridyl or 4-pyridyl. In certain embodiments, R⁴ is 3-pyridyl. In certain embodiments, R⁴ is substituted 2-pyridyl, substituted 3-pyridyl or substituted 4-pyridyl.

In certain embodiments, R⁵ is alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, heteroaryl, or substituted heteroaryl. In some embodiments, R⁵ is alkyl or substituted alkyl. In some embodiments, R⁵ is alkenyl or substituted alkenyl. In some embodiments, R⁵ is cycloalkyl or substituted cycloalkyl. In some embodiments, R⁵ is heterocycloalkyl or substituted heterocycloalkyl. In some embodiments, R⁵ is aryl or substituted aryl. In some embodiments, R⁵ is heteroaryl or substituted heteroaryl.

For example, in embodiments where R⁵ is alkyl, R⁵ may be C₁₋₆ alkyl, or C₁₋₅ alkyl, or C₁₋₄ alkyl, or C₁₋₃ alkyl, or C₁₋₂ alkyl. In some instances, R⁵ is methyl. In other embodiments, R⁵ may be substituted alkyl, such as for example substituted C₁₋₆ alkyl, or substituted C₁₋₅ alkyl, or substituted C₁₋₄ alkyl, or substituted C₁₋₃ alkyl, or substituted C₁₋₂ alkyl.

In certain embodiments, R⁵ is aryl or substituted aryl. For example, in embodiments where R⁵ is aryl, R⁵ may be phenyl.

In other embodiments, R⁵ is substituted aryl, such as for example substituted phenyl. In certain embodiments, the substituent on the aryl group in a substituted aryl is C₁₋₆ alkyl, or C₁₋₅ alkyl, or C₁₋₄ alkyl, or C₁₋₃ alkyl, or C₁₋₂ alkyl. In certain embodiments, the substituent on the aryl group in the substituted aryl is methyl. For example, the substituted aryl may be a substituted phenyl, such as where the substituent on the phenyl group in the substituted phenyl is C₁₋₆ alkyl, or C₁₋₅ alkyl, or C₁₋₄ alkyl, or C₁₋₃ alkyl, or C₁₋₂ alkyl. In certain embodiments, the substituent on the phenyl group in the substituted phenyl is methyl. For example, R⁵ may be 2-methylphenyl, 3-methylphenyl, or 4-methylphenyl. In certain embodiments, R⁵ is 4-methylphenyl.

In certain embodiments, the substituent on the aryl group in a substituted aryl is a halogen. The substituted aryl may include one or more halogen substituents, such as 5, 4, 3, 2, or 1 halogen substituents. In embodiments of the substituted aryl that include more than one halogen substituent, each halogen substituent is independently selected from fluoro, chloro, bromo, and iodo. In some instances, the substituted aryl includes one halogen substituent. The halogen substituent may be selected from fluoro, chloro, bromo, and iodo. In some instances, the halogen substituent is fluoro. For example, the substituted aryl may be a substituted phenyl, such as where the substituent on the phenyl group in the substituted phenyl is a halogen. As described above, the substituted phenyl may include one or more halogen substituents, such as 5, 4, 3, 2, or 1 halogen substituents. In embodiments of the substituted phenyl that include more than one halogen substituent, each halogen substituent is independently selected from fluoro, chloro, bromo, and iodo. In some instances, the substituted phenyl includes one halogen substituent. The halogen substituent may be selected from fluoro, chloro, bromo, and iodo. In some instances, the halogen substituent is fluoro. For example, R⁵ may be 2-fluorophenyl, 3-fluorophenyl, or 4-fluorophenyl. In certain embodiments, R⁵ is 4-fluorophenyl.

Particular compounds disclosed herein, and salts or solvates or stereoisomers thereof, include:

-   Compound 1:     N⁵-((2R)-1-((carboxymethyl)amino)-3-((1-(4-methyl-5-oxo-4,5-dihydro-1H-tetrazol-1-yl)-2-tosylethyl)thio)-1-oxopropan-2-yl)-L-glutamine; -   Compound 2:     N⁵-((2R)-1-((carboxymethyl)amino)-3-((3-methoxy-3-oxo-1-(5-oxo-4-(pyridin-3-yl)-4,5-dihydro-1H-tetrazol-1-yl)propyl)thio)-1-oxopropan-2-yl)-L-glutamine; -   Compound 3: methyl     N-acetyl-S-(1-(4-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)-2-(phenylsulfonyl)ethyl)-L-cysteinate; -   Compound 4:     N-acetyl-S-(1-(4-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)-2-(phenylsulfonyl)ethyl)-L-cysteine; -   Compound 5:     (2R)-2-amino-3-(1-(4-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)-2-(phenylsulfonyl)ethylthio)propanoic     acid; -   Compound 6:     (2S)-2-amino-5-((2R)-1-(carboxymethylamino)-3-(1-(4-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)-2-(phenylsulfonyl)ethylthio)-1-oxopropan-2-ylamino)-5-oxopentanoic     acid; -   Compound 7:     2-acetamido-4-(1-(4-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)-2-(phenylsulfonyl)ethylthio)butanoic     acid; -   Compound 8:     (2R)-2-acetamido-3-(1-(4-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)-2-(phenylsulfonyl)ethylthio)propanamide; -   Compound 9: methyl     N-acetyl-S-(3-methoxy-3-oxo-1-(5-oxo-4-(pyridin-3-yl)-4,5-dihydro-1H-tetrazol-1-yl)propyl)-L-cysteinate;     and -   Compound 10: methyl     N-acetyl-S-(1-(4-methyl-5-oxo-4,5-dihydro-1H-tetrazol-1-yl)-2-tosylethyl)-L-cysteinate.

In certain embodiments, the compound has the structure:

In certain embodiments, the compound has the structure:

In certain embodiments, the compound has the structure:

In certain embodiments, the compound has the structure:

In certain embodiments, the compound has the structure:

In certain embodiments, the compound has the structure:

In certain embodiments, the compound has the structure:

In certain embodiments, the compound has the structure:

In certain embodiments, the compound has the structure:

In certain embodiments, the compound has the structure:

In certain embodiments, the prodrug is compound that is a conjugate of dimethylfumarate (DMF) and glutathione (GSH). For instance, glutathione may include a thiol group, where the thiol group is used to form a thioether linkage between glutathione and dimethylfumarate to produce a prodrug as described herein. As described herein, the prodrug can undergo an in vivo transformation when administered to a subject, such as a cleavage reaction, at a desired site of action such that glutathione and dimethylfumarate are released at the site of action. For example, the prodrug may be a compound having the structure:

N⁵-((2R)-1-((carboxymethyl)amino)-3-((1,4-dimethoxy-1,4-dioxobutan-2-yl)thio)-1-oxopropan-2-yl)-L-glutamine (Compound 11)

In certain embodiments, the prodrug is compound that is a conjugate of dimethylfumarate and a thiol-containing compound. For instance, the thiol-containing compound may include a thiol group, where the thiol group is used to form a thioether linkage between the thiol-containing compound and dimethylfumarate to produce a prodrug as described herein. As described herein, the prodrug can undergo an in vivo transformation when administered to a subject, such as a cleavage reaction, at a desired site of action such that dimethylfumarate and the thiol-containing compound are released at the site of action. For example, the prodrug may be a compound having the structure:

dimethyl 2-(((R)-2-(acetyl-λ²-azaneyl)-3-methoxy-3-oxopropyl)thio)succinate (Compound 12).

The prodrugs, compounds, conjugates and adducts described herein can be isolated by procedures known to those skilled in the art. The prodrugs, compounds, conjugates and adducts described herein may be obtained, for instance, by a resolution technique or by chromatography techniques (e.g., silica gel chromatography, chiral chromatography, etc.). As used herein, the term “isolated” refers to compounds that are non-naturally occurring and can be obtained or purified from synthetic reaction mixtures. Isolated compounds may find use in the pharmaceutical compositions and methods of treatment described herein.

The compounds described also include isotopically labeled compounds where one or more atoms have an atomic mass different from the atomic mass conventionally found in nature. Examples of isotopes that may be incorporated into the compounds disclosed herein include, but are not limited to, ²H, ³H, ¹¹C, ¹³C, ¹⁴C, ¹⁵N, ¹⁸O, ¹⁷O, etc. Thus, the disclosed compounds may be enriched in one or more of these isotopes relative to the natural abundance of such isotope. By way of example, deuterium (²H; D) has a natural abundance of about 0.015%. Accordingly, for approximately every 6,500 hydrogen atoms occurring in nature, there is one deuterium atom. Specifically contemplated herein are compounds enriched in deuterium at one or more positions. Thus, deuterium containing compounds of the disclosure have deuterium at one or more positions (as the case may be) in an abundance of greater than 0.015%. In some embodiments, one or more (e.g., 1, 2, 3, 4, 5, 6, 7 or more) hydrogen atoms of an R¹ group of any one of the subject compounds described herein are substituted with a deuterium.

Pharmaceutical Compositions

In certain embodiments, the disclosed compounds are useful for the treatment of a disease or disorder, such as an autoimmune or an inflammatory disease or disorder. Accordingly, pharmaceutical compositions comprising at least one disclosed compound are also described herein. For example, the present disclosure provides pharmaceutical compositions that include a pharmaceutically acceptable carrier and a therapeutically effective amount of a compound of the present disclosure or a pharmaceutically acceptable salt or solvate or stereoisomer thereof.

A pharmaceutical composition that includes a subject compound may be administered to a patient alone, or in combination with other supplementary active agents. For example, one or more compounds according to the present disclosure can be administered to a patient with or without supplementary active agents. The pharmaceutical compositions may be manufactured using any of a variety of processes, including, but not limited to, conventional mixing, dissolving, granulating, dragee-making, levigating, emulsifying, encapsulating, entrapping, lyophilizing, and the like. The pharmaceutical composition can take any of a variety of forms including, but not limited to, a sterile solution, suspension, emulsion, spray dried dispersion, lyophilisate, tablet, microtablets, pill, pellet, capsule, powder, syrup, elixir or any other dosage form suitable for administration.

A subject compound may be administered to a subject using any convenient means capable of resulting in the desired reduction in disease condition or symptom. Thus, a subject compound can be incorporated into a variety of formulations for therapeutic administration. More particularly, a subject compound can be formulated into pharmaceutical compositions by combination with appropriate pharmaceutically acceptable carriers or diluents, and may be formulated into preparations in solid, semi-solid, liquid or gaseous forms, such as tablets, capsules, powders, granules, ointments, solutions, suppositories, injections, inhalants, aerosols, and the like.

Formulations for pharmaceutical compositions are described in, for example, Remington's Pharmaceutical Sciences, by E. W. Martin, Mack Publishing Co., Easton, Pa., 19th Edition, 1995, which describes examples of formulations (and components thereof) suitable for pharmaceutical delivery of disclosed compounds. Pharmaceutical compositions that include at least one of the subject compounds can be formulated for use in human or veterinary medicine. Particular formulations of a disclosed pharmaceutical composition may depend, for example, on the mode of administration and/or on the location of the subject to be treated. In some embodiments, formulations include a pharmaceutically acceptable carrier in addition to at least one active ingredient, such as a subject compound. In other embodiments, other medicinal or pharmaceutical agents, for example, with similar, related or complementary effects on the disease or condition being treated can also be included as active ingredients in a pharmaceutical composition.

Pharmaceutically acceptable carriers useful for the disclosed methods and compositions may depend on the particular mode of administration being employed. For example, parenteral formulations may include injectable fluids, such as, but not limited to, pharmaceutically and physiologically acceptable fluids such as water, physiological saline, balanced salt solutions, aqueous dextrose, glycerol or the like as a vehicle. For solid compositions (e.g., powder, pill, tablet, or capsule forms), non-toxic solid carriers can include, for example, pharmaceutical grades of mannitol, lactose, starch, or magnesium stearate. In addition to biologically neutral carriers, pharmaceutical compositions to be administered can optionally contain minor amounts of non-toxic auxiliary substances (e.g., excipients), such as wetting or emulsifying agents, preservatives, and pH buffering agents and the like; for example, sodium acetate or sorbitan monolaurate. Other examples of excipients include, nonionic solubilizers, such as cremophor, or proteins, such as human serum albumin or plasma preparations.

Some examples of materials which can serve as pharmaceutically-acceptable carriers include: (1) sugars, such as lactose, glucose and sucrose; (2) starches, such as corn starch and potato starch; (3) cellulose, and its derivatives, such as sodium carboxymethyl cellulose, ethyl cellulose and cellulose acetate; (4) powdered tragacanth; (5) malt; (6) gelatin; (7) talc; (8) excipients, such as cocoa butter and suppository waxes; (9) oils, such as peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil and soybean oil; (10) glycols, such as propylene glycol; (11) polyols, such as glycerin, sorbitol, mannitol, and polyethylene glycol; (12) esters, such as ethyl oleate and ethyl laurate; (13) agar; (14) buffering agents, such as magnesium hydroxide and aluminum hydroxide; (15) alginic acid; (16) water (e.g., pyrogen-free water); (17) isotonic saline; (18) Ringer's solution; (19) ethyl alcohol; (20) pH buffered solutions; (21) polyesters, polycarbonates and/or polyanhydrides; and (22) other non-toxic compatible substances employed in pharmaceutical formulations.

The disclosed pharmaceutical compositions may be formulated as a pharmaceutically acceptable salt of a disclosed compound. Examples of pharmaceutically acceptable salts include non-toxic salts of a free base form of a compound that possesses the desired pharmacological activity of the free base. These salts may be derived from inorganic or organic acids. Non-limiting examples of suitable inorganic acids are hydrochloric acid, nitric acid, hydrobromic acid, sulfuric acid, hydroiodic acid, and phosphoric acid. Non-limiting examples of suitable organic acids are acetic acid, propionic acid, glycolic acid, lactic acid, pyruvic acid, malonic acid, succinic acid, malic acid, maleic acid, fumaric acid, tartaric acid, citric acid, benzoic acid, cinnamic acid, mandelic acid, methanesulfonic acid, ethanesulfonic acid, methyl sulfonic acid, salicylic acid, formic acid, trichloroacetic acid, trifluoroacetic acid, gluconic acid, asparagic acid, aspartic acid, benzenesulfonic acid, para-toluenesulfonic acid, naphthalenesulfonic acid, combinations thereof, and the like. In certain embodiments, the pharmaceutically acceptable salt includes formic acid. Other examples of pharmaceutically acceptable salts include non-toxic salts of a free acid form of compounds according to the present disclosure. Such salts are derived from inorganic or organic bases. Pharmaceutically acceptable base addition salts include those derived from inorganic bases such as sodium, potassium, lithium, ammonium, calcium, magnesium, iron, zinc, copper, manganese, aluminum salts, combinations thereof, and the like. Examples of salts are the ammonium, potassium, sodium, calcium, and magnesium salts. Salts of the presently disclosed compounds can be derived from pharmaceutically acceptable organic non-toxic bases including, but not limited to, salts of primary, secondary, and tertiary amines, substituted amines including naturally occurring substituted amines, cyclic amines and basic ion exchange resins, such as isopropylamine, trimethylamine, diethylamine, triethylamine, tripropylamine, ethanolamine, 2-dimethylaminoethanol, 2-diethylaminoethanol, 2-amino-2-hydroxymethyl-propane-1,3-diol (“Tris” salt), dicyclohexylamine, lysine, arginine, histidine, caffeine, procaine, hydrabamine, choline, betaine, ethylenediamine, glucosamine, methylglucamine, theobromine, purines, piperazine, piperidine, N-ethylpiperidine, combinations thereof, and the like. Pharmaceutically acceptable salts are described further in S. M. Berge, et al., “Pharmaceutical Salts,” J. Pharm. Sci., 1977; 66:1-19 and Remington's Pharmaceutical Sciences, 19th Edition, Mack Publishing Company, Easton, Pa., 1995.

A subject compound can be used alone or in combination with appropriate additives to make tablets, powders, granules or capsules, for example, with conventional additives, such as lactose, mannitol, corn starch or potato starch; with binders, such as crystalline cellulose, cellulose derivatives, acacia, corn starch or gelatins; with disintegrators, such as corn starch, potato starch or sodium carboxymethylcellulose; with lubricants, such as talc or magnesium stearate; and if desired, with diluents, buffering agents, moistening agents, preservatives and flavoring agents. Such preparations can be used for oral administration.

A subject compound can be formulated into preparations for injection by dissolving, suspending or emulsifying the compound in an aqueous or nonaqueous solvent, such as vegetable or other similar oils, synthetic aliphatic acid glycerides, esters of higher aliphatic acids or propylene glycol; and if desired, with conventional additives such as solubilizers, isotonic agents, suspending agents, emulsifying agents, stabilizers and preservatives. The preparation may also be emulsified or the active ingredient encapsulated in liposome vehicles. Formulations suitable for injection can be administered by an intravitreal, intraocular, intramuscular, subcutaneous, sublingual, or other route of administration, e.g., injection into the gum tissue or other oral tissue. Such formulations are also suitable for topical administration.

In some embodiments, a subject compound can be delivered by a continuous delivery system. The term “continuous delivery system” is used interchangeably herein with “controlled delivery system” and encompasses continuous (e.g., controlled) delivery devices (e.g., pumps) in combination with catheters, injection devices, and the like, a wide variety of which are known in the art.

A subject compound can be utilized in aerosol formulation to be administered via inhalation. A subject compound can be formulated into pressurized acceptable propellants such as dichlorodifluoromethane, propane, nitrogen and the like.

Furthermore, a subject compound can be made into suppositories by mixing with a variety of bases such as emulsifying bases or water-soluble bases. A subject compound can be administered rectally via a suppository. The suppository can include vehicles such as cocoa butter, carbowaxes and polyethylene glycols, which melt at body temperature, yet are substantially solid at room temperature.

The term “unit dosage form,” as used herein, refers to physically discrete units suitable as unitary dosages for human and animal subjects, each unit containing a predetermined quantity of a subject compound calculated in an amount sufficient to produce the desired effect in association with a pharmaceutically acceptable diluent, carrier or vehicle. The specifications for a subject compound depend on the particular compound employed and the effect to be achieved, and the pharmacodynamics associated with each compound in the host.

The dosage form of a disclosed pharmaceutical composition may be determined by the mode of administration chosen. For example, in addition to injectable fluids, topical or oral dosage forms may be employed. Topical preparations may include eye drops, ointments, sprays and the like. Oral formulations may be liquid (e.g., syrups, solutions or suspensions), or solid (e.g., powders, pills, tablets, or capsules). Methods of preparing such dosage forms are known, or will be apparent, to those skilled in the art.

Certain embodiments of the pharmaceutical compositions that include a subject compound may be formulated in unit dosage form suitable for individual administration of precise dosages. The amount of active ingredient administered may depend on the subject being treated, the severity of the affliction, and the manner of administration, and is known to those skilled in the art. In certain instances, the formulation to be administered contains a quantity of the compounds disclosed herein in an amount effective to achieve the desired effect in the subject being treated.

Each therapeutic compound can independently be in any dosage form, such as those described herein, and can also be administered in various ways, as described herein. For example, the compounds may be formulated together, in a single dosage unit (that is, combined together in one form such as capsule, tablet, powder, or liquid, etc.) as a combination product. Alternatively, when not formulated together in a single dosage unit, an individual subject compound may be administered at the same time as another therapeutic compound or sequentially, in any order thereof.

A disclosed compound can be administered alone, as the sole active pharmaceutical agent, or in combination with one or more additional compounds of the present disclosure or in conjunction with other agents. When administered as a combination, the therapeutic agents can be formulated as separate compositions that are administered simultaneously or at different times, or the therapeutic agents can be administered together as a single composition combining two or more therapeutic agents. Thus, the pharmaceutical compositions disclosed herein containing a compound of the present disclosure optionally include other therapeutic agents. Accordingly, certain embodiments are directed to such pharmaceutical compositions, where the composition further includes a therapeutically effective amount of an agent selected as is known to those of skill in the art.

Methods of Administration

The subject compounds find use for treating a disease or disorder in a subject, such as an autoimmune or an inflammatory disease or disorder. The route of administration may be selected according to a variety of factors including, but not limited to, the condition to be treated, the formulation and/or device used, the patient to be treated, and the like. Routes of administration useful in the disclosed methods include but are not limited to oral and parenteral routes, such as intravenous (iv), intraperitoneal (ip), rectal, topical, ophthalmic, nasal, and transdermal. Formulations for these dosage forms are described herein.

An effective amount of a subject compound may depend, at least, on the particular method of use, the subject being treated, the severity of the affliction, and the manner of administration of the therapeutic composition. A “therapeutically effective amount” of a composition is a quantity of a specified compound sufficient to achieve a desired effect in a subject (e.g., patient) being treated. For example, this may be the amount of a subject compound necessary to prevent, inhibit, reduce or relieve a disease or disorder in a subject, such as an autoimmune or an inflammatory disease or disorder. Ideally, a therapeutically effective amount of a compound is an amount sufficient to prevent, inhibit, reduce or relieve a disease or disorder in a subject without causing a substantial cytotoxic effect on host cells in the subject.

Therapeutically effective doses of a subject compound or pharmaceutical composition can be determined by one of skill in the art, with a goal of achieving local (e.g., tissue) concentrations that are at least as high as the EC₅₀ of an applicable compound disclosed herein.

An example of a dosage range is from 0.1 to 200 mg/kg body weight orally in single or divided doses. In some embodiments, a dosage range is from 1.0 to 100 mg/kg body weight orally in single or divided doses, including from 1.0 to 50 mg/kg body weight, from 1.0 to 25 mg/kg body weight, from 1.0 to 10 mg/kg body weight (assuming an average body weight of approximately 70 kg; values may be adjusted accordingly for persons weighing more or less than average). For oral administration, the compositions are, for example, provided in the form of a tablet containing from about 10 to about 1000 mg of the active ingredient, such as 25 to 750 mg, or 50 to 500 mg, for example 75 mg, 100 mg, 200 mg, 250 mg, 400 mg, 500 mg, 600 mg, 750 mg, or 1000 mg of the active ingredient for the symptomatic adjustment of the dosage to the subject being treated. In certain embodiments of an oral dosage regimen, a tablet containing from 500 mg to 1000 mg active ingredient is administered once (e.g., a loading dose) followed by administration of ½ (i.e., half) dosage tablets (e.g., from 250 to 500 mg) each 6 to 24 hours for 3 days or more.

The specific dose level and frequency of dosage for any particular subject may be varied and may depend upon a variety of factors, including the activity of the subject compound, the metabolic stability and length of action of that compound, the age, body weight, general health, sex and diet of the subject, mode and time of administration, rate of excretion, drug combination, and severity of the condition of the host undergoing therapy.

Embodiments of the present disclosure also include combinations of one or more disclosed compounds with one or more other agents or therapies useful in the treatment of a disease or disorder. In certain instances, the disease or disorder is an autoimmune or an inflammatory disease or disorder. In certain instances, the disease or disorder is psoriasis, such as plaque psoriasis. In certain instances, the disease or disorder is multiple sclerosis. For example, one or more disclosed compounds may be administered in combination with therapeutically effective doses of other medicinal and pharmaceutical agents, or in combination other non-medicinal therapies, such as hormone (e.g., corticosteroids) or radiation therapy (e.g., phototherapy). The term “administration in combination with” refers to both concurrent and sequential administration of the active agents.

Methods of Treatment

The compounds described in the present disclosure are useful for treating a disease or disorder, such as a disease or disorder caused by oxidative stress (e.g., oxidative stress caused by injury or an autoimmune or an inflammatory disease or disorder), in a subject in need of treatment. In certain instances, the disease or disorder is one that is amenable to treatment by an antioxidant, such as by one or more antioxidant proteins. In certain instances, the disease or disorder is one that is amenable to treatment by an increase in expression of antioxidant protein(s) in a subject in need of treatment. In certain instances, the disease or disorder is one that is amenable to treatment by an increase in expression of antioxidant protein(s), where the expression of the antioxidant protein(s) is regulated by Nrf2, in a subject in need of treatment.

In certain instances, the disease or disorder is an autoimmune or an inflammatory disease or disorder. In certain instances, the disease or disorder is psoriasis, such as plaque psoriasis. In certain instances, the disease or disorder is multiple sclerosis. Other diseases that can be treated with the compounds disclosed herein include pulmonary arterial hypertension (PAH), non-alcoholic and alcoholic steatohepatitis, traumatic brain injury, radiation exposure and exposure to toxic chemicals such as cyanide.

Accordingly, the present disclosure provides methods of treating an inflammatory disease in a subject by administering an effective amount of a subject compound, including a salt or solvate or stereoisomer thereof, so as to treat inflammation. For example, the present disclosure provides a method of treating an inflammatory disease in a subject. In certain embodiments, the method includes administering to the subject (e.g., patient) a compound of the present disclosure, or a salt or solvate or stereoisomer thereof.

In addition, the present disclosure also provides methods of treating an autoimmune disease in a subject by administering to the subject an effective amount of a subject compound, including a salt or solvate or stereoisomer thereof, so as to treat the autoimmune disease. For example, the present disclosure also provides a method of treating an autoimmune disease in a subject. In certain embodiments, the method includes administering to the subject (e.g., patient) a compound of the present disclosure, or a salt or solvate or stereoisomer thereof.

In certain embodiments, compounds useful in the methods of treatment disclosed herein (e.g., for treating an autoimmune or inflammatory disease or disorder) include compounds of formula (I), (Ia), (Ib), (II), (IIa), and (IIb), as disclosed herein.

In certain embodiments, the compound useful in the methods of treatment disclosed herein (e.g., for treating an autoimmune or inflammatory disease or disorder) is a compound of the following structure:

In certain embodiments, the compound useful in the methods of treatment disclosed herein (e.g., for treating an autoimmune or inflammatory disease or disorder) is a compound of the following structure:

In certain embodiments, the compound useful in the methods of treatment disclosed herein (e.g., for treating an autoimmune or inflammatory disease or disorder) is a compound of the following structure:

In certain embodiments, the compound useful in the methods of treatment disclosed herein (e.g., for treating an autoimmune or inflammatory disease or disorder) is a compound of the following structure:

In certain embodiments, the compound useful in the methods of treatment disclosed herein (e.g., for treating an autoimmune or inflammatory disease or disorder) is a compound of the following structure:

In certain embodiments, the compound useful in the methods of treatment disclosed herein (e.g., for treating an autoimmune or inflammatory disease or disorder) is a compound of the following structure:

In certain embodiments, the compound useful in the methods of treatment disclosed herein (e.g., for treating an autoimmune or inflammatory disease or disorder) is a compound of the following structure:

In certain embodiments, the compound useful in the methods of treatment disclosed herein (e.g., for treating an autoimmune or inflammatory disease or disorder) is a compound of the following structure:

In certain embodiments, the compound useful in the methods of treatment disclosed herein (e.g., for treating an autoimmune or inflammatory disease or disorder) is a compound of the following structure:

In certain embodiments, the compound useful in the methods of treatment disclosed herein (e.g., for treating an autoimmune or inflammatory disease or disorder) is a compound of the following structure:

In certain embodiments, the compound useful in the methods of treatment disclosed herein (e.g., for treating an autoimmune or inflammatory disease or disorder) is a compound of the following structure:

In certain embodiments, the compound useful in the methods of treatment disclosed herein (e.g., for treating an autoimmune or inflammatory disease or disorder) is a compound of the following structure:

Diseases or conditions for treatment according to the present disclosure include, but are not limited to, psoriasis, multiple sclerosis, inflammatory bowel disease, asthma, chronic obstructive pulmonary disease, and arthritis. For example, diseases or conditions for treatment according to the present disclosure include, but are not limited to, immunological, autoimmune, and/or inflammatory diseases including: psoriasis such as plaque psoriasis; asthma; chronic obstructive pulmonary diseases (COPD) such as bronchitis, emphysema, as well as other lung disorders such as asbestosis, pneumoconiosis, and pulmonary neoplasms; arthritis such as inflammatory arthritis, including rheumatoid arthritis, juvenile rheumatoid arthritis (juvenile idiopathic arthritis), psoriatic arthritis, and ankylosing spondylitis produce joint inflammation; cardiac insufficiency including left ventricular insufficiency, myocardial infarction and angina pectoris; mitochondrial and neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, Huntington's disease, amyotrophic lateral sclerosis (ALS or Lou Gehrig's Disease), retinopathia pigmentosa and mitochondrial encephalomyopathy; transplantation rejection; autoimmune diseases including multiple sclerosis, ischemia and reperfusion injury, AGE-induced genome damage; inflammatory bowel diseases (IBD) such as Crohn's disease and ulcerative colitis; and NF-κB mediated diseases.

Further diseases or conditions for treatment according to the present disclosure include, but are not limited to, rheumatica, granuloma annulare, lupus, autoimmune carditis, eczema, sarcoidosis, and autoimmune diseases including acute disseminated encephalomyelitis, Addison's disease, alopecia areata, ankylosing spondylitis, antiphospholipid antibody syndrome, autoimmune hemolytic anemia, autoimmune hepatitis, autoimmune inner ear disease, bullous pemphigoid, Behcet's disease, celiac disease, Chagas disease, chronic obstructive pulmonary disease, Crohn's disease, dermatomyositis, diabetes mellitus type I, endometriosis, Goodpasture's syndrome, Graves' disease, Guillain-Barre syndrome, Hashimoto's disease, hidradenitis suppurativea, Kawasaki disease, IgA neuropathy, idiopathic thrombocytopenic purpura, interstitial cystitis, lupus erythematosus, mixed connective tissue disease, morphea, multiple sclerosis, myasthenia gravis, narcolepsy, neuromyotonia, pemphigus vulgaris, pernicious anaemia, psoriasis, psonatic arthritis, polymyositis, primary biliary cirrhosis, rheumatoid arthritis, schizophrenia, scleroderma, Sjogren's syndrome, stiff person syndrome, temporal arteritis, ulcerative colitis, vasculitis, vitiligo, and Wegener's granulomatosis.

Additional diseases or conditions for treatment according to the present disclosure include, but are not limited to, necrobiosis lipodica, granuloma annulare, sarcoidosis, alopecia areata, cheilitis granulomatosa, recurrent oral aphthae, non-infectious chronic uveitis, pityriasis rubra pilaris, annular elastolytic giant cell granuloma, and the like. Diseases or conditions for treatment according to the present disclosure also include Huntington's disease, malaria, HIV, HIV-associated neurodegenerative disorders, bronchial asthma, myocardial infarction, chronic obstructive pulmonary disease, HSV1 keratitis, and immunosuppression due to organ transplantation.

In certain embodiments, the subject compounds are useful for treating a disease or disorder, such as cell proliferative disorders. Cell proliferative disorders treatable with the subject compound disclosed herein relate to any disorder characterized by aberrant cell proliferation. These include various tumors and cancers, benign or malignant, metastatic or non-metastatic. Specific properties of cancers, such as tissue invasiveness or metastasis, can be targeted using the methods described herein. Cell proliferative disorders include a variety of cancers, including, among others, breast cancer, colon cancer, melanoma, glioblastoma, ovarian cancer, renal cancer, gastrointestinal cancer, kidney cancer, bladder cancer, pancreatic cancer, lung squamous carcinoma, and adenocarcinoma.

Compounds of the present disclosure may also find use as research tools. Accordingly, the present disclosure also provides for a method for using a compound of the present disclosure or a salt or solvate or stereoisomer thereof as a research tool for studying a biological system or sample, or for discovering new chemical compounds having use for treating a an autoimmune or an inflammatory disease or disorder in a subject.

Embodiments are also directed to a compound of the present disclosure or a salt or solvate or stereoisomer thereof, for use in therapy or as a medicament. For instance, embodiments include the use of a compound of the present disclosure or a salt or solvate or stereoisomer thereof, for the manufacture of a medicament; for example, for the manufacture of a medicament for the treatment of an autoimmune or inflammatory disease or disorder. In some cases, the embodiments are also directed to the use of a compound of the present disclosure or a salt or solvate or stereoisomer thereof for the manufacture of a medicament for the treatment of an autoimmune disease, such as multiple sclerosis. The embodiments are also directed to the use of a compound of the present disclosure or a salt or solvate or stereoisomer thereof for the manufacture of a medicament for the treatment of an inflammatory disease or disorder, such as psoriasis. Further diseases or conditions for treatment according to the present disclosure are discussed above.

Characterization of Functional Properties

The following are examples of assays useful in characterizing activities of a compound of the present disclosure.

A. In Vitro

1. Glutathione Depletion Assay

In one aspect the present compounds exert their therapeutic effects by acting as a Michael acceptor for reactive thiol groups in vivo. See, for example, Lehmann et al. Dimethylfumarate Induces Immunosuppression via Glutathione Depletion and Subsequent Induction of Heme Oxygenase 1, Journal of Investigative Dermatology (2007) 127, 835-845. Accordingly, the present compounds may be assessed in vitro by reaction with glutathione as follows:

A mixture of dimethylfumarate (5.2 mg, 3.6 mmol) and reduced glutathione (22.4 mg, 7.3 mmol; 2 equiv.) in d₆-DMSO (1.2 mL) were combined in a screw-top vial and the mixture was stirred at 35° C. (with the top securely fastened). Aliquots of sample were removed at intermittent time points and a ¹H NMR taken [note: after analysis by ¹H NMR, the sample can be returned to the heated vial and reaction continued). ¹H NMR indicates majority reaction with glutathione (by Michael addition to the double bond) after 3 hr, and complete reaction by 27 hr.

The above reaction was repeated using monomethylfumarate (11.4 mg, 8.8 mmol) and reduced glutathione (55.5 mg, 18.0 mmol) in d₆-DMSO (3.0 mL) at 35° C. As judged by ¹H NMR, majority reaction was observed by 27 hr.

The above reaction was repeated using methyl (E)-3-(5-oxo-4,5-dihydro-1H-tetrazol-1-yl)acrylate (6.2 mg, 3.6 mmol) and reduced glutathione (22.4 mg, 7.2 mmol) in d₆-DMSO (1.2 mL) at 35° C. As judged by ¹H NMR, majority reaction was observed by 30 hr.

The above reaction was repeated using methyl (E)-3-(4-methyl-5-oxo-4,5-dihydro-1H-tetrazol-1-yl)acrylate (6.6 mg, 3.6 mmol) and reduced glutathione (22.4 mg, 7.2 mmol) in d₆-DMSO (1.2 mL) at 35° C. As judged by ¹H NMR, majority reaction was observed by 30 hr.

In all the above cases, dis-appearance of the alkene proton signals from the starting material are used to determine the extent of Michael reaction with glutathione.

As would be understood by those of skill in the art, the above experiments can be repeated by varying the equivalents of reduced glutathione (0.5 to 2 equivalents); the reactions can also be run in a mixture of d₆-DMSO and D₂O; and the temperature of the reaction can also be varied from room temperature to 35° C. (35° C. being used to mimic body temperature). As used herein “majority reaction” means a greater than 50% reduction in alkene proton signal as observed by ¹H NMR.

Other in vitro assays well known to those of skill in the art can be used to demonstrate the anti-inflammatory efficacy of the present compounds. For example, certain compounds blocked production of the inflammatory cytokine IL-23 in THP1 cells stimulated with LPS.

B. In Vivo

1. Mouse Experimental Autoimmune Encephalomyelitis Assay

The in vivo efficacy of a compound towards autoimmune diseases can be demonstrated in a mouse model of experimental autoimmune encephalomyelitis (EAE).

Model Description: EAE is a useful model for multiple sclerosis (MS), an autoimmune disease of the CNS that is caused by immune-cell infiltration of the CNS white matter. Inflammation and subsequent destruction of myelin cause progressive paralysis. Like the human disease, EAE is associated with peripheral activation of T cells autoreactive with myelin proteins, such as myelin basic protein (MBP), proteolipid protein (PLP), or myelin oligodendrocyte protein (MOG). Activated neuroantigen-specific T cells pass the blood-brain barrier, leading to focal mononuclear cell infiltration and demyelination. EAE can be induced in susceptible mouse strains by immunization with myelin-specific proteins in combination with adjuvant. In the SJL mouse model used in these studies, hind limb and tail paralysis is apparent by Day 10 after immunization, the peak of disease severity can be observed between Days 10 and 14, and a cycle of partial spontaneous remission followed by relapse can be observed up to Day 35. The results can demonstrate the potential of a compound to suppress disease severity and prevent relapse of disease symptoms that may be the result of FcγR-mediated cytokine release from immune cells.

Study Protocol: In the SJL murine model of EAE, each mouse is sensitized with proteolipid protein (PLP)/complete Freund's adjuvant (CFA). (150 g PLP₁₃₉-1₅₁ with 200 μg CFA in 0.05 ml of homogenate on four sites of hind flank for a total of 0.2 ml emulsion is used to induce EAE). In a suppression protocol, either vehicle or various doses of a test compound are administered via oral gavage starting on the day of immunization (Day 0). In a treatment protocol, at onset of disease, animals are separated to achieve groups with a similar mean clinical score at onset and administered vehicle or various dose frequencies of test compounds via oral gavage. In both protocols, clinical scores are monitored daily, and body weights are measured twice weekly.

Determination of Results: By 10 days after PLP immunization, SJL mice can develop clinical EAE, as evidenced by an increase in their mean clinical scores. The paralytic score can gradually increase in the animals treated with vehicle only from the day of immunization (Day 0), and by Day 14 the mean score can reach a peak of about 5.1. At disease peak (e.g., Day 14), the mean clinical score in animals treated with either daily or twice daily can be significantly reduced. By Day 16, animals can exhibit a partial remission of mean clinical severity, which is a characteristic of the SJL model. The lower clinical scores in animals treated twice daily with a test compound can remain significant throughout the experiment until the animals are sacrificed on Day 30. These lower scores throughout the treatment period are reflected in the significantly lower cumulative disease index (CDI) and increase in cumulative weight index (CWI).

SJL mice treated with a test compound at disease onset (e.g., Day 11) can show a significant decrease in CDI. Further, there can be a decrease in the number of relapses in animals treated with a test compound compared with the number of relapses in animals treated with vehicle.

2. Experimental Autoimmune Encephalomyelitis Animal Model

The in vivo therapeutic efficacy of a compound for treating autoimmune diseases, such as multiple sclerosis, can be assessed in an experimental autoimmune encephalomyelitis (EAE) animal model.

Animals and EAE Induction: Female C57BL/6 mice, 8-10 weeks old are immunized subcutaneously in the flanks and mid-scapular region with 200 g of myelin oligodendrocyte glycoprotein peptide (MOG₃₅₋₅₅) emulsified (1:1 volume ratio) with complete Freund's adjuvant (CFA) (containing 4 mg/mL Mycobacterium tuberculosis). The emulsion is prepared by the syringe-extrusion method with two glass Luer-Lock syringes connected by a 3-way stopcock. Mice are also given an intraperitoneal injection of 200 ng pertussis toxin on the day of immunization and on day two post immunization. Mice are weighed and examined daily for clinical signs of experimental autoimmune encephalomyelitis (EAE). Food and water is provided ad libitum and once animals start to show disease, food is provided on the cage bottom.

Treatment Protocol: Solutions containing various concentrations of a test compound are administered by oral gavage twice daily to different treatment groups starting from day 3 post-immunization until termination. Dexamethasone is dissolved in 1×PBS buffer (1 mg/kg) and administered subcutaneously once daily.

Clinical Evaluation: Mice are scored daily beginning on day 7 post immunization. The clinical scoring scale is as follows: 0=normal; 1=limp tail or hind limb weakness (defined by foot slips between bars of cage top while walking); 2=limp tail and hind limb weakness; 3=partial hind limb paralysis (defined as no weight bearing on hind limbs but can still move one or both hind limbs to some extent); 4=complete hind limb paralysis; 5=moribund state (includes forelimb paralysis) or death. In some embodiments, compound 1 (methyl (E)-3-(5-oxo-4,5-dihydro-1H-tetrazol-1-yl)acrylate) significantly prevents the onset of disease paralysis when dosed at 60 mg/kg beginning on the day of immunization.

3. Animal Model to Assess Therapeutic Efficacy in Treating Psoriasis

The in vivo therapeutic efficacy of a compound for treating psoriasis can be assessed in an experimental animal model. For example, the severe, combined immunodeficient (SCID) mouse model can be used to evaluate the efficacy of compounds for treating psoriasis in humans.

SCID mice are used as tissue recipients. One biopsy for each normal or psoriatic volunteer is transplanted onto the dorsal surface of a recipient mouse. Treatment is initiated 1 to 2 weeks after transplantation. Animals with the human skin transplants are divided into treatment groups. Animals are treated twice daily for 14 days. At the end of treatment, animals are photographed and then euthanized. The transplanted human tissue along with the surrounding mouse skin is surgically removed and fixed in 10% formalin and samples obtained for microscopy. Epidermal thickness is measured. Tissue sections are stained with an antibody to the proliferation-associated antigen Ki-67 and with an anti-human CD3⁺ monoclonal antibody to detect human T lymphocytes in the transplanted tissue. Sections are also probed with antibodies to c-myc and β-catenin. A positive response to treatment is reflected by a reduction in the average epidermal thickness of the psoriatic skin transplants. A positive response is also associated with reduced expression of Ki-67 in keratinocytes.

4. Animal Model to Assess Therapeutic Efficacy in Treating Multiple Sclerosis

The in vivo therapeutic efficacy of a compound for treating multiple sclerosis can be assessed in an experimental animal model.

Experiments are conducted on female C57BL/6 mice aged 4-6 weeks and weighing 17-20 g. Experimental autoimmune encephalomyelitis (EAE) is actively induced using ≥95% pure synthetic myelin oligodendrocyte glycoprotein peptide 35-55 (MOG₃₅₋₅₅, MEVGWYRSPFSRVVHLYRNGK) (SEQ ID NO:1). Each mouse is anesthetized and receives 200 μg of MOG peptide and 15 g of Saponin extract from Quilija bark emulsified in 100 μL of phosphate-buffered saline. A 25 μL volume is injected subcutaneously over four flank areas. Mice are also intraperitoneally injected with 200 ng of pertussis toxin in 200 μL of PBS. A second, identical injection of pertussis toxin is given after 48 h.

A test compound is administered at varying doses. Control animals receive 25 μL of DMSO. Daily treatment extends from day 26 to day 36 post-immunization. Clinical scores are obtained daily from day 0 post-immunization until day 60. Clinical signs are scored using the following protocol: 0, no detectable signs; 0.5, distal tail limpness, hunched appearance and quiet demeanor; 1, completely limp tail; 1.5, limp tail and hind limb weakness (unsteady gait and poor grip with hind limbs); 2, unilateral partial hind limb paralysis; 2.5, bilateral hind limb paralysis; 3, complete bilateral hind limb paralysis; 3.5, complete hind limb paralysis and unilateral forelimb paralysis; 4, total paralysis of hind limbs and forelimbs.

Inflammation and demyelination are assessed by histology on sections from the CNS of EAE mice. Mice are euthanized after 30 or 60 days and whole spinal cords are removed and placed in 0.32 M sucrose solution at 4° C. overnight. Tissues are prepared and sectioned. Luxol fast blue stain is used to observe areas of demyelination. Haematoxylin and eosin staining is used to highlight areas of inflammation by darkly staining the nuclei of mononuclear cells. Immune cells stained with H&E are counted in a blinded manner under a light microscope. Sections are separated into gray and white matter and each sector is counted manually before being combined to give a total for the section. T cells are immunolabeled with anti-CD3⁺ monoclonal antibody. After washing, sections are incubated with goat anti-rat HRP secondary antibody. Sections are then washed and counterstained with methyl green. Splenocytes isolated from mice at 30 and 60 days post-immunization are treated with lysis buffer to remove red blood cells. Cells are then resuspended in PBS and counted. Cells at a density of about 3×10⁶ cells/mL are incubated overnight with 20 μg/mL of MOG peptide. Supernatants from stimulated cells are assayed for IFN-γ protein levels using an appropriate mouse IFN-γ immunoassay system.

Research Applications

Since subject compounds find use for the treatment of autoimmune and inflammatory diseases and disorders, such compounds are also useful as research tools. The present disclosure also provides a method for using the subject compounds as a research tool for studying a biological system or sample, or for discovering new chemical compounds that can be used for the treatment of autoimmune and inflammatory diseases and disorders, such as psoriasis or multiple sclerosis.

The disclosure provides for a method of studying a biological system or sample known to be associated with an autoimmune or inflammatory disease or disorder, the method comprising: (a) contacting the biological sample with a compound of the present disclosure or a salt or solvate or stereoisomer thereof; and (b) determining the efficacy of the compound on treating the biological sample.

Any suitable biological sample can be employed in such studies which can be conducted either in vitro or in vivo. Representative biological samples suitable for such studies include, but are not limited to, cells, cellular extracts, plasma membranes, tissue samples, isolated organs, mammals (such as mice, rats, guinea pigs, rabbits, dogs, pigs, humans, and so forth), and the like, with mammals being of particular interest.

When used as a research tool, a biological sample is typically contacted with a pharmaceutically effective amount of a subject compound. After the biological sample is exposed to the compound, the effects of the compound are determined using conventional procedures and equipment, such as the assays disclosed herein. Exposure encompasses contacting the biological sample with the compound or administering the compound to a subject. The determining step can involve measuring a response (a quantitative analysis) or can involve making an observation (a qualitative analysis). Measuring a response involves, for example, determining the effects of the compound on the biological sample using conventional procedures and equipment, such as radioligand binding assays and measuring ligand-mediated changes in functional assays. The assay results can be used to determine the activity level as well as the amount of compound necessary to achieve the desired result, that is, a pharmaceutically effective amount.

Additionally, the subject compounds can be used as research tools for evaluating other chemical compounds, and thus are also useful in screening assays to discover, for example, new compounds useful for the treatment of an autoimmune or inflammatory disease or disorder. In this manner, a subject compound can be used as a standard in an assay to allow comparison of the results obtained with a test compound and with the subject compounds to identify those test compounds that have about equal or superior activity, if any. For example, EC₅₀ data for a test compound or a group of test compounds is compared to the EC₅₀ data for a subject compound to identify those test compounds that have the desired properties, for example, test compounds having an EC₅₀ about equal or superior to a subject compound, if any.

This aspect includes, as separate embodiments, both the generation of comparison data (using the appropriate assays) and the analysis of test data to identify test compounds of interest. Thus, a test compound can be evaluated in a biological assay, by a method comprising the steps of: (a) conducting a biological assay with a test compound to provide a first assay value; (b) conducting the biological assay with a subject compound to provide a second assay value; where step (a) is conducted either before, after or concurrently with step (b); and (c) comparing the first assay value from step (a) with the second assay value from step (b). The assays that can be used for generation of comparison data are disclosed herein, such as the mouse EAE assays.

General Synthetic Procedures

Many general references providing commonly known chemical synthetic schemes and conditions useful for synthesizing the disclosed compounds are available (see, e.g., Smith and March, March's Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, Fifth Edition, Wiley-Interscience, 2001; or Vogel, A Textbook of Practical Organic Chemistry, Including Qualitative Organic Analysis, Fourth Edition, New York: Longman, 1978).

Compounds as described herein can be purified by any purification protocol known in the art, including chromatography, such as HPLC, preparative thin layer chromatography, flash column chromatography and ion exchange chromatography. Any suitable stationary phase can be used, including normal and reversed phases as well as ionic resins. In certain embodiments, the disclosed compounds are purified via silica gel and/or alumina chromatography. See, e.g., Introduction to Modern Liquid Chromatography, 2nd Edition, ed. L. R. Snyder and J. J. Kirkland, John Wiley and Sons, 1979; and Thin Layer Chromatography, ed E. Stahl, Springer-Verlag, New York, 1969.

During any of the processes for preparation of the subject compounds, it may be necessary and/or desirable to protect sensitive or reactive groups on any of the molecules concerned. This may be achieved by means of conventional protecting groups as described in standard works, such as J. F. W. McOmie, “Protective Groups in Organic Chemistry”, Plenum Press, London and New York 1973, in T. W. Greene and P. G. M. Wuts, “Protective Groups in Organic Synthesis”, Third edition, Wiley, New York 1999, in “The Peptides”; Volume 3 (editors: E. Gross and J. Meienhofer), Academic Press, London and New York 1981, in “Methoden der organischen Chemie”, Houben-Weyl, 4^(th) edition, Vol. 15/1, Georg Thieme Verlag, Stuttgart 1974, in H.-D. Jakubke and H. Jescheit, “Aminosauren, Peptide, Proteine”, Verlag Chemie, Weinheim, Deerfield Beach, and Basel 1982, and/or in Jochen Lehmann, “Chemie der Kohlenhydrate: Monosaccharide and Derivate”, Georg Thieme Verlag, Stuttgart 1974. The protecting groups may be removed at a convenient subsequent stage using methods known from the art.

The subject compounds can be synthesized via a variety of different synthetic routes using commercially available starting materials and/or starting materials prepared by conventional synthetic methods. All of the compounds described herein can be prepared by adaptation of these methods.

Stereoisomers of the compounds can be isolated by procedures known to those skilled in the art. The individual stereoisomers may be obtained, for instance, by a resolution technique or by chromatography techniques (e.g., silica gel chromatography, chiral chromatography, etc.).

Although the synthetic schemes discussed herein may not illustrate the use of protecting groups, skilled artisans will recognize that in some instances certain substituents may include functional groups requiring protection. The exact identity of the protecting group used will depend upon, among other things, the identity of the functional group being protected and the reaction conditions used in the particular synthetic scheme, and will be apparent to those of skill in the art. Guidance for selecting protecting groups, their attachment and removal suitable for a particular application can be found, for example, in Greene & Wuts, supra.

In certain embodiments, in the above methods, the method further includes separating isomers with a resolution technique. In certain embodiments, in the above methods, the method further includes separating isomers with chiral chromatography. In certain embodiments, the disclosure provides a method for preparing an optically active compound.

In some embodiments, the above methods further include the step of forming a salt of a compound disclosed herein. Embodiments are directed to the other processes described herein, and to the product prepared by any of the processes described herein.

In some instances, the subject compounds are prepared according to one of the generic synthetic Schemes A-D depicted below.

where each R′ and R″ independently can be any convenient groups as described herein. In some cases, R′ is alkyl or substituted alkyl. In some cases, R″ is alkyl (e.g., methyl), substituted alkyl, heteroaryl (e.g., 3-pyridyl), substituted heteroaryl, aryl or substituted aryl.

In some instances, the subject compounds are prepared via the strategy depicted in Scheme A via reaction of a substituted acetylenic sulfone with a 1-substituted-1H-tetrazol-5(4H)-one. Acetylenic sulfones which find use in the preparation of the subject compounds via Scheme A can be prepared by adapting those methods described in U.S. Publication No. 2011/0281177, the disclosure of which is incorporated herein by reference. 1-Substituted-1H-tetrazol-5(4H)-ones can be prepared using any convenient procedure.

where each R′ and R″ independently can be any convenient groups as described herein. In some cases, R′ is alkyl or substituted alkyl. In some cases, R″ is alkyl (e.g., methyl), substituted alkyl, heteroaryl (e.g., 3-pyridyl), substituted heteroaryl, aryl or substituted aryl.

In some instances, the subject compounds are prepared via the strategy depicted in Scheme B via reaction of a dimeric vinyl sulfone and a 1-substituted-1H-tetrazol-5(4H)-one. Dimeric vinyl sulfones which find use in the preparation of the subject compounds via Scheme B can be prepared by adapting those methods described by Tiecco et al. (J. Org. Chem. 1983, 48, 4795-4800), the disclosure of which is incorporated herein by reference. 1-Substituted-1H-tetrazol-5(4H)-ones can be prepared using any convenient procedure.

where X is a leaving group (e.g., a halogen) and each R′ and R″ independently can be any convenient groups as described herein. In some cases, R′ is alkyl or substituted alkyl. In some cases, R″ is alkyl (e.g., methyl), substituted alkyl, heteroaryl (e.g., 3-pyridyl), substituted heteroaryl, aryl or substituted aryl.

In some instances, the subject compounds are prepared via the strategy depicted in Scheme C via reaction of a monomeric vinyl sulfone with a 1-substituted-1H-tetrazol-5(4H)-one. Vinyl sulfones which find use in the preparation of the subject compounds via Scheme C can be prepared by adapting those methods described by Guan et al. (Synthesis 2007, 10, 1465-70), the disclosure of which is incorporated herein by reference. 1-Substituted-1H-tetrazol-5(4H)-ones can be prepared using any convenient procedure.

where each R′ and R″ independently can be any convenient groups as described herein. In some cases, R′ is alkyl or substituted alkyl. In some cases, R″ is alkyl (e.g., methyl), substituted alkyl, heteroaryl (e.g., 3-pyridyl), substituted heteroaryl, aryl or substituted aryl.

In some instances, the subject compounds are prepared via the strategy depicted in Scheme D from a sulfonyl acrylic acid which is converted into a tetrazolone intermediate and then further substituted at the 1-position with any convenient substituent (R″). The sulfonyl acrylic acid starting material (e.g., (E)-3-(methylsulfonyl)acrylic acid) which finds use in the preparation of the subject compounds via Scheme D can be prepared by adapting those methods described by Guan et al. (Synthesis 2007, 10, 1465-70), the disclosure of which is incorporated herein by reference. The sulfonyl acrylic acid can be converted to a tetrazolone using a variety of methods. In some cases, the sulfonyl acrylic acid is activated (e.g., to an acyl chloride or an acyl azide) which is further reacted with an azide reagent (e.g., trimethylsilyl azide, TMS-N₃) to produce the intermediate 1H-tetrazol-5(4H)-one. For example, the conversion of sulfonyl acrylic acid can be achieved by reaction with the reagent diphenylphosphoryl azide followed by trimethylsilyl azide. Alternatively, the conversion of sulfonyl acrylic acid can be achieved by reaction with the reagent oxalyl chloride followed by trimethylsilyl azide.

The tetrazolone intermediate can then be further substituted at the 1-position using a variety of methods. In some cases, substitution can be achieved using an alkyl halide reagent under basic conditions. In some cases, a nucleophilic aromatic substitution reaction can be performed to include an aryl or heteroaryl substituent at the 1-position.

In some embodiments of the synthetic schemes A-D described herein R′ is an alkyl (e.g., methyl) or a substituted alkyl (e.g., isopropyl or tert-butyl). In some embodiments of the synthetic schemes A-D described herein R′ is an aryl (e.g., phenyl) or a substituted aryl (e.g., 4-methylphenyl).

Schemes A-D described herein may be used to synthesize Nrf2 activating compounds as disclosed herein. Subsequent reaction of the Nrf2 activating compound with a second moiety can be used to synthesize a prodrug as described herein. Examples of such synthetic routes that can be used to synthesize the prodrugs disclosed herein are described in the Examples below.

EXAMPLES

The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how to make and use the embodiments, and are not intended to limit the scope of what the inventors regard as their invention nor are they intended to represent that the experiments below are all or the only experiments performed. Efforts have been made to ensure accuracy with respect to numbers used (e.g. amounts, temperature, etc.) but some experimental errors and deviations should be accounted for. As will be understood, by those of skill in the art of organic synthesis and medicinal chemistry the specific conditions set forth below are exemplary and can be varied or adapted to other reagents and products in routine fashion. Unless indicated otherwise, parts are parts by weight, molecular weight is weight average molecular weight, temperature is in degrees Celsius, and pressure is at or near atmospheric. Standard abbreviations may be used.

Example 1: Synthesis of N⁵-((2R)-1-((Carboxymethyl)amino)-3-((1-(4-methyl-5-oxo-4,5-dihydro-1H-tetrazol-1-yl)-2-tosylethyl)thio)-1-oxopropan-2-yl)-L-glutamine (Compound 1)

To a solution of (E)-1-methyl-4-(2-tosylvinyl)-1,4-dihydro-5H-tetrazol-5-one (100, 100 mg, 0.36 mmol), glutathione (GSH) (200, 110 mg, 0.36 mmol) in MeOH/H₂O (5 mL, 1:1), TEA (5 μL, 3.6 mg, 36 μmol)) was added. The heterogeneous reaction mixture was then allowed to stir at 60° C. for 2 days, cooled down to room temperature and concentrated to give a white solid. Reverse phase chromatography provided 101 mg (48%) of 1:1 diastereomeric mixture of N⁵-((2R)-1-((carboxymethyl)amino)-3-((1-(4-methyl-5-oxo-4,5-dihydro-1H-tetrazol-1-yl)-2-tosylethyl)thio)-1-oxopropan-2-yl)-L-glutamine (1) as a white solid.

¹H NMR (400 MHz, CD₃OD) δ 7.73-7.65 (m, 2H), 7.44-7.36 (m, 2H), 5.93 (dd, J=11.3, 2.3 Hz, 0.5H), 5.80 (dd, J=11.4, 2.6 Hz, 0.5H), 4.81 (dd, J=9.5, 4.6 Hz, 0.5H), 4.49 (dd, J=8.8, 5.0 Hz, 0.5H), 4.39 (ddd, J=14.3, 11.3, 2.8 Hz, 1H), 3.93 (dd, J=4.4, 2.5 Hz, 0.5H), 3.89 (dd, J=4.5, 2.5 Hz, 0.5H), 3.88 (s, 1H), 3.86 (d, J=2.3 Hz, 1H), 3.69 (t, J=5.9 Hz, 0.5H), 3.63 (t, J=6.2 Hz, 0.5H), 3.46 (s, 3H), 3.20 (dd, J=14.2, 5.0 Hz, 0.5H), 3.05 (dd, J=14.4, 4.6 Hz, 0.5H), 2.94 (dd, J=14.2, 8.8 Hz, 0.5H), 2.74 (dd, J=14.4, 9.5 Hz, 0.5H), 2.57 (t, J=6.2 Hz, 1H), 2.49 (q, J=6.7 Hz, 1H), 2.45 (s, 3H), 2.12 (dp, J=18.7, 6.6 Hz, 2H).

¹³C NMR (101 MHz, CD₃OD) δ 175.74, 175.15, 173.78, 173.45, 173.35, 172.32, 172.26, 151.57, 151.30, 147.09, 147.07, 136.99, 136.94, 131.18, 129.46, 57.96, 57.53, 56.67, 55.54, 55.04, 54.38, 53.05, 42.44, 42.43, 34.47, 33.93, 33.04, 33.01, 31.79, 31.72, 27.74, 27.48, 21.73.

MS m/e: 588 (M+H)⁺.

Example 2: Synthesis of N⁵-((2R)-1-((Carboxymethyl)amino)-3-((1,4-dimethoxy-1,4-dioxobutan-2-yl)thio)-1-oxopropan-2-yl)-L-glutamine (Compound 11)

To a solution of dimethyl fumarate (400, 100 mg, 0.69 mmol), GSH (200, 215 mg, 0.70 mmol) in MeOH/H₂O (5 mL, 1:1), TEA (10 μL, 7.3 mg, 72 μmol)) was added. The heterogeneous reaction mixture was then allowed to stir at 60° C. for 2 hrs. and at room temperature for 3 days, cooled down to room temperature and concentrated to give a white solid. Reverse phase chromatography provided 139 mg (44%) of 1:1 diastereomeric mixture of N⁵-((2R)-1-((carboxymethyl)amino)-3-((1-(4-methyl-5-oxo-4,5-dihydro-1H-tetrazol-1-yl)-2-tosylethyl)thio)-1-oxopropan-2-yl)-L-glutamine (11) as a white solid.

¹H NMR (400 MHz, CD₃OD) δ 8.15 (s, 1H), 4.67-4.61 (m, 1H), 3.90 (s, 2H), 3.81-3.77 (m, 1H), 3.75, 3.74 (2s, 3H), 3.67, (s, 3H), 3.67 (t, J=6.3 Hz, 1H), 3.23 (ddd, J=14.1, 9.0, 5.1 Hz, 1H), 3.03-2.84 (m, 2H), 2.74 (dd, J=36.4, 5.5 Hz, 0.5H), 2.74 (dd, J=5.9, 2.3 Hz, 0.5H), 2.56-2.52 (m, 2H), 2.21-2.06 (m, 2H).

MS m/e: 452 (M+H)⁺.

Example 3: Synthesis of N⁵-((2R)-1-((Carboxymethyl)amino)-3-((3-methoxy-3-oxo-1-(5-oxo-4-(pyridin-3-yl)-4,5-dihydro-1H-tetrazol-1-yl)propyl)thio)-1-oxopropan-2-yl)-L-glutamine (Compound 2)

To a solution of methyl (E)-3-(5-oxo-4-(pyridin-3-yl)-4,5-dihydro-1H-tetrazol-1-yl)acrylate (600, 100 mg, 0.4 mmol), GSH (200, 0.125 mg, 0.41 mmol) in MeOH/H₂O (5 mL, 1:1), TEA (6 μL, 4.4 mg, 43 μmol)) was added. The heterogeneous reaction mixture was then allowed to stir at 60° C. for 3 days, cooled down to room temperature and concentrated to give a white solid. Reverse phase chromatography provided 75 mg (33%) of 1:1 diastereomeric mixture of N⁵-((2R)-1-((carboxymethyl)amino)-3-((3-methoxy-3-oxo-1-(5-oxo-4-(pyridin-3-yl)-4,5-dihydro-1H-tetrazol-1-yl)propyl)thio)-1-oxopropan-2-yl)-L-glutamine (2) as a white solid.

¹H NMR (400 MHz, CD₃OD) δ 9.17 (t, J=2.7 Hz, 1H), 8.61 (dd, J=4.7, 1.2 Hz, 1H), 8.42-8.39, (m, 1H), 8.13 (s, 1H), 7.64 (d, J=5.1 Hz, 0.5H), 7.62 (d, J=4.7 Hz, 0.5H), 5.95-5.86 (m, 1H), 4.63-4.59 (m, 0.5H), 3.90 (s, 1H), 3.88 (s, 1H), 3.69 (s, 3H), 3.65 (t, J=6.3 Hz, 0.5H), 3.61 (t, J=6.3 Hz, 0.5H), 3.47-3.38 (m, 1H), 3.34-3.21 (m, 2H), 3.06 (dd, J=14.1, 9.0 Hz, 0.5H), 2.89 (dd, J=14.5, 9.4 Hz, 0.5H), 2.57-2.47 (m, 2H), 2.18-2.14 (m, 2H).

MS m/e: 555 (M+H)⁺.

Example 4: Synthesis of Methyl N-Acetyl-S-(1-(4-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)-2-(phenylsulfonyl)ethyl)-L-cysteinate (Compound 3)

To a solution of (E)-4-methyl-2-(2-(phenylsulfonyl)vinyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (800, 400 mg, 1.5 mmol), N—Ac-L-Cys-OMe (900, 300 mg, 1.7 mmol) in MeOH/H₂O (3 mL, 1:1), TEA (21 μL, 15.2 mg, 150 μmol)) was added. The heterogeneous reaction mixture was then allowed to stir at 50° C. for 2 days, cooled down to room temperature and concentrated to give a white solid. Column chromatography, eluting with 2-10% MeOH/DCM, provided 506 mg (76%) of 3:2 diastereomeric mixture of methyl N-acetyl-S-(1-(4-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)-2-(phenylsulfonyl)ethyl)-L-cysteinate (3) as a white solid.

¹H NMR (400 MHz, CDCl₃) δ 7.91-7.83 (m, 2H), 7.67-7.60 (m, 1H), 7.56-7.51 (m, 2H), 7.21 (s, 0.4H), 7.18 (s, 0.6H), 7.02 (d, J=8.2 Hz, 0.4H), 6.49 (d, J=7.0 Hz, 0.6H), 5.91 (dd, J=10.9, 2.4 Hz, 0.4H), 5.83 (dd, J=10.4, 2.8 Hz, 0.6H), 4.90-4.78 (m, 1H), 4.23 (ddd, J=14.7, 10.6, 2.9 Hz, 1H), 3.76 (s, 1.8H), 3.75 (s, 1.2H), 3.54 (dd, J=14.7, 2.9 Hz, 0.6H), 3.48 (dd, J=14.7, 2.4 Hz, 0.4H), 3.22 (s, 1.2H), 3.17 (s, 1.8H), 3.13 (dd, J=14.1, 4.6 Hz, 0.6H), 3.03-2.97 (m, 0.4H), 2.95 (dd, J=14.2, 5.6 Hz, 0.6H), 2.87 (dd, J=14.7, 7.2 Hz, 0.4H), 2.10 (s, 1.2H), 2.07 (s, 1.8H).

¹³C NMR (101 MHz, CDCl₃) δ 170.95, 170.84, 170.68, 170.33, 153.41, 152.85, 138.79, 138.74, 137.52, 137.29, 134.07, 134.01, 129.32, 129.26, 128.61, 128.54, 57.91, 57.76, 54.44, 54.09, 53.41, 53.07, 53.00, 52.61, 32.96, 32.42, 29.17, 29.05, 23.27, 23.25.

MS m/e: 443 (M+H)⁺.

Example 5: Synthesis of N-Acetyl-S-(1-(4-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)-2-(phenylsulfonyl)ethyl)-L-cysteine (Compound 4)

To a solution of (E)-4-methyl-2-(2-(phenylsulfonyl)vinyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (800, 50 mg, 0.19 mmol), N—Ac-L-Cys-OH (1100, 35 mg, 0.21 mmol) in MeOH/H₂O (3 mL, 1:1), TEA (150 μL, 110 mg, 1.1 mmol)) was added. The heterogeneous reaction mixture was then allowed to stir at 50° C. for 2 days, cooled down to room temperature and concentrated to give a white solid. Reverse phase chromatography provided 49 mg (61%) of 2:1 diastereomeric mixture of N-acetyl-S-(1-(4-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)-2-(phenylsulfonyl)ethyl)-L-cysteine (4) as a white solid.

¹H NMR (400 MHz, DMSO-d₆) δ 8.23 (d, J=8.2 Hz, 0.66H), 8.16 (d, J=7.9 Hz, 0.34H), 7.76-7.65 (m, 3H), 7.63 (s, 0.34H), 7.62 (s, 0.66H), 7.61-7.54 (m, 2H), 5.59 (ddd, J=11.1, 4.6, 2.3 Hz, 1H), 4.39-4.14 (m, 2H), 3.86 (td, J=14.5, 2.4 Hz, 1H), 2.99 (s, 1H), 2.98 (s, 2H), 2.94-2.77 (m, 1.34H), 2.72 (dd, J=13.5, 8.4 Hz, 0.66H), 1.83 (s, 2H), 1.82 (s, 1H).

¹³C NMR (101 MHz, DMSO-d₆) δ 171.66, 171.65, 169.24, 169.23, 152.07, 152.00, 138.42, 138.33, 138.22, 138.17, 133.87, 133.83, 128.99, 128.95, 127.76, 127.65, 56.78, 56.64, 53.49, 53.20, 52.25, 51.30, 31.67, 31.52, 28.28, 28.25, 22.33, 22.30.

MS m/e: 429 (M+H)⁺.

Example 6: General Synthesis of Prodrug Compounds

A mixture of methyl (E)-3-(5-oxo-4-(pyridin-3-yl)-4,5-dihydro-1H-tetrazol-1-yl)acrylate (0.1 g, 0.40 mmol), methyl acetyl-L-cysteinate (0.08 g, 0.44 mmol), and triethylamine (6 μl, 0.04 mmol) in methanol (2 mL) was stirred at room temperature for 5 h. The reaction mixture was then concentrated under reduced pressure to give a residue, which was purified by chromatography eluting with ethyl acetate/hexanes (7/3) to provide methyl N-acetyl-S-(3-methoxy-3-oxo-1-(5-oxo-4-(pyridin-3-yl)-4,5-dihydro-1H-tetrazol-1-yl)propyl)-L-cysteinate (9) as an off-white solid (0.12 g, 73%).

¹H NMR (CD₃OD, 400 MHz) δ 9.14 (m, 1H), 8.06 (m, 1H), 8.36 (m, 1H), 7.62 (m, 1H), 5.85 (m, 1H), 4.68 (m, 1H), 3.67 (m, 6H), 3.39 (m, 1H), 3.23 (m, 2H), 3.06 (m, 1H), 1.96 (m, 3H).

¹³C NMR (CD₃OD, 100 MHz) δ 171.84, 171.67, 170.74, 170.66, 169.33, 169.24, 148.27, 148.22, 148.17, 140.31, 140.15, 131.81, 127.67, 127.49, 124.31, 57.24, 56.89, 56.14, 52.29, 51.84, 51.62, 51.61, 37.68, 37.11, 33.05, 32.23, 20.92, 20.87, 16.94.

MS m/e: 425.1 (M+H)⁺.

Compounds 10 and 12 were also prepared using the general synthetic scheme described above for Compound 9.

Methyl N-acetyl-S-(1-(4-methyl-5-oxo-4,5-dihydro-1H-tetrazol-1-yl)-2-tosylethyl)-L-cysteinate (Compound 10)

¹H NMR (CDCl₃, 400 MHz) δ 7.71 (m, 2H), 7.33 (m, 2H), 6.52 (m, 1H), 5.82 (m, 1H), 4.86 (m, 1H), 4.31 (m, 1H), 3.76 (m, 3H), 3.59 (m, 1H), 3.50 (m, 3H), 3.08 (m, 2H), 2.44 (s, 3H), 2.06 (m, 3H).

MS m/e: 458.2 (M+H)⁺.

Dimethyl 2-(((R)-2-(Acetyl-λ²-azaneyl)-3-methoxy-3-oxopropyl)thio)succinate (Compound 12)

¹H NMR (CDCl₃, 400 MHz) δ 6.62 (m, 1H), 4.92 (m, 1H), 3.73 (m, 10H), 3.22 (m, 1H), 3.11 (m, 1H), 2.95 (m, 1H), 2.67 (m, 1H), 2.06 (m, 3H).

¹³C NMR (CDCl₃, 100 MHz) δ 171.92, 171.88, 171.20, 170.88, 170.82, 170.80, 170.11, 169.92, 52.79, 52.75, 52.72, 52.22, 52.13, 52.04, 51.96, 42.26, 41.97, 36.39, 35.86, 34.26, 34.02, 23.05, 22.30.

MS m/e: 322.1 (M+H)⁺.

Example 7: Biological Activity of Compounds

Autoimmune Encephalitis (EAE) In Vivo Assay

Compounds disclosed herein are tested in an autoimmune encephalitis (EAE) in vivo assay in mice according to the methods described above in the paragraph entitled B.2. Experimental Autoimmune Encephalomyelitis Animal Model. For example, compounds of the present disclosure are useful for preventing the onset of disease paralysis when dosed at 60 mg/kg beginning on the day of immunization.

NrF2 Activation in a Whole Cell Nuclear Translocation Assay

Compounds are tested in a NrF2 (Nuclear factor (erythroid-derived 2)-like 2) translocation assay by adapting the methods set forth in U.S. Pat. No. 8,101,373, the disclosure of which is incorporated herein by reference. A result of NrF2 activation in the assay by the present compounds is an indication of their anti-inflammatory activity.

Monomethyl fumarate and dimethyl fumarate have NrF2 activation with EC50s of about 127 and 7.9 micromolar, respectively. Examples of compounds disclosed herein may show comparable activity to monomethyl fumarate and dimethyl fumarate in the NrF2 translocation assay. In addition to monomethyl fumarate and dimethyl fumarate, bardoxolone methyl may be used as a positive control.

While the present invention has been described with reference to the specific embodiments thereof, it should be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the true spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, process, process step or steps, to the objective, spirit and scope of the present invention. All such modifications are intended to be within the scope of the claims appended hereto. 

What is claimed is:
 1. A method of treating a disease of disorder in a subject in need thereof, the method comprising: administering to the subject a pharmaceutically effective amount of a compound of formula (I):

wherein: R² is selected from the group consisting of sulfonyl, carboxyl, carboxyl ester, and aminoacyl; R³ is selected from the group consisting of an active agent, an antioxidant, an amino acid, an amino acid derivative, a peptide, and a peptide derivative; R⁴ is selected from the group consisting of hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, heteroaryl, and substituted heteroaryl; X¹ and X² are each independently selected from N and CH, wherein at least one of X¹ and X² is N; and n is an integer from 1 to 6, or a salt or a stereoisomer thereof, wherein the administering is sufficient to treat the disease or disorder, and wherein the disease or disorder is selected from the group consisting of cardiac insufficiency, asthma, arthritis, an inflammatory bowel disease, and a chronic obstructive pulmonary disease.
 2. The method of claim 1, wherein R² is sulfonyl or carboxyl ester.
 3. The method of claim 1, wherein the compound is a compound of formula (II):

wherein: R³ is selected from the group consisting of an active agent, an antioxidant, an amino acid, an amino acid derivative, a peptide, and a peptide derivative; R⁴ is selected from the group consisting of hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, heteroaryl, and substituted heteroaryl; R⁵ is selected from the group consisting of alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, heterocyclyl, substituted heterocyclyl, aryl, substituted aryl, heteroaryl, and substituted heteroaryl; X¹ and X² are each independently selected from N and CH, wherein at least one of X¹ and X² is N; and n is an integer from 1 to 6, or a salt or a stereoisomer thereof.
 4. The method of claim 3, wherein R⁵ is aryl or substituted aryl.
 5. The method of claim 1, wherein n is
 1. 6. The method of claim 1, wherein n is
 2. 7. The method of claim 1, wherein R³ is glutathione.
 8. The method of claim 1, wherein R³ is an amino acid or an amino acid derivative.
 9. The method of claim 1, wherein X¹ is N and X² is N.
 10. The method of claim 1, wherein X¹ is N and X² is CH.
 11. The method of claim 1, wherein the compound is selected from the group consisting of:


12. The method of claim 1, wherein the disease or disorder is cardiac insufficiency.
 13. The method of claim 12, wherein the cardiac insufficiency is selected from the group consisting of left ventricular insufficiency, myocardial infarction, and angina pectoris.
 14. The method of claim 1, wherein the disease or disorder is asthma.
 15. The method of claim 1, wherein the disease or disorder is arthritis.
 16. The method of claim 15, wherein the arthritis is selected from the group consisting of inflammatory arthritis, rheumatoid arthritis, juvenile rheumatoid arthritis (juvenile idiopathic arthritis), psoriatic arthritis, and ankylosing spondylitis.
 17. The method of claim 1, wherein the disease or disorder is an inflammatory bowel disease.
 18. The method of claim 17, wherein the inflammatory bowel disease is selected from the group consisting of Crohn's disease and ulcerative colitis.
 19. The method of claim 1, wherein the disease or disorder is a chronic obstructive pulmonary disease.
 20. The method of claim 19, wherein the chronic obstructive pulmonary disease is selected from the group consisting of bronchitis and emphysema. 